As evidenced by the hype surrounding the show's 60th anniversary special, Doctor Who is one of the most popular science fiction franchises of all time. Despite its longevity, the series has remained fresh and inventive thanks to its premise of an ever-changing alien who has adventures through time and space. The penchant for creative reinvention and progress is baked into the show's DNA.
Beyond the central conceit of traveling across space and time, one of the reasons Doctor Who remains popular is because of its complex characters. With the Doctor, audiences were given an enigmatic space traveler who occasionally showed glimpses of humanity while his companions offered a down to Earth contrast to his personality. Despite how charming the dynamic between Doctor and companion is, the series has never been afraid to show its characters commit morally dubious acts (such as the ones highlighted by Redditors).
The First Doctor Nearly Commits Murder
The general perception of the First Doctor among Whovians is that he was an old, grumpy, but kind gentleman, who held a couple of antiquated attributes (which were grossly played up in "Once Upon a Time"). As a deleted Redditor pointed out however, the First Doctor isn't as kind as people make him out to be given he "attempted to crush an unconcious [sic] man's skull with a large rock and was only stopped by one of his companions" in Doctor Who's first ever episode."
While the First Doctor started out on an unsavory note and a morally questionable figure, his time with Ian and Barbara allowed for him to grow as an individual. Over the course of three seasons, he went from someone willing to kidnap and murder to protect himself, to a champion of human ideals, working to save the Earth from alien threats.
Amy's Behavior Towards Rory
Amy Pond is one of the more contentious Doctor Who companions. While she has a wonderful friendship with the Doctor and is crucial to the dynamic of one of the most endearing TARDIS teams, her relationship with her husband, Rory, has faced quite a few problems - with many fans taking issue with how she treated him on several occasions.
As this Redditor states, they "couldn't stand how cold she was towards him and how she always seemed annoyed that he was tagging along" - especially when Rory had been nothing but kind and helpful. Considering that Rory was going to be the person she wanted to spend the rest of her life with, it really did sit right with the viewers that she, initially, didn't want to be around him.
The Second Doctor Deceives His Companions
One of the smarter incarnations of the Doctor, Two was a conniving trickster who did an exceptional job of letting others believe he was a buffoon. While this use of deception was primarily used against aliens attempting to conquer the Earth or obtain power, the Second Doctor also lied to his companions from time to time.
In the eyes of Redditor notwherebutwhen, the Second Doctor's most questionable actions came in the story, "Enemy of the World," where he "tricks his companions into thinking he is Salamander at one point." It's a decision that feels callous considering the Second Doctor's kindly nature, but forgivable when considering the events of the story.
The Brigadier Destroys The Silurians
Brigadier Alistair Gordon Lethbridge-Stewart is one of the Doctor's greatest allies. As head of UNIT, he aided the Doctor in defending the Earth from all sorts of alien invasions and domestic threats, though this hasn't stopped the Brigadier from committing awful military actions.
When discussing the moral failings of several Doctor Who characters, this Reddit user noted that the Brigadier killed "an entire tribe of Silurians after the Doctor tries to teach him about the sanctity of life." It was an incident that colored the Third Doctor's perception of the Brigadier for much of his time on Earth, though the two would eventually reconcile.
The Sixth Doctor's Erratic Post-Regeneration Behavior
The Sixth Doctor is generally seen as the least likable incarnation of the Doctor. This is largely due to his ego, braggadocio, and cantankerous relationship with Peri, though one listen to his audio adventures proves these qualities are largely over-embellished by the character to protect himself given his sensitive nature.
Despite the attempts of numerous writers to redeem the Sixth Doctor, the fact remains that the show's hero will always be remembered by Redditor Torranski and others for the time he "spent preening about his new appearance and strangling a scared young woman." It was a nonsensical decision on the part of the writers, and one which will forever taint an otherwise noble character.
Rose's Treatment Of Her Mother And Boyfriend
Rose was the audience surrogate character for Doctor Who when it came back in 2005. She was witty, outspoken, and curious, attributes which make for a great Doctor Who companion for new viewers.
While Rose's personality was a wonderful counter to the Ninth and Tenth Doctor, her relationships with other people were less endearing. Redditor Febrifuge, in particular, called the character out for how "terribly rude [Rose was] to her own mom," and for the way "she walked all over poor Mickey." The latter ultimately resulted in the character staying in an alternate dimension just to get away from Rose.
The Eleventh Doctor's Callousness
The Eleventh Doctor is generally seen as one of the sillier incarnations of the Time Lord, and for his aged wisdom, which lurked beneath his youthful veneer. While this latter quality often lent the character a sort of grandfatherly warmth, it also resulted in some cold moments of moral superiority.
According to Redditor hohmeisw, the Eleventh Doctor's callousness was most present when he left "Old Amy behind to die horribly" in "The Girl Who Waited." In one of the most shocking scenes in Doctor Who history, the Doctor reads as the villain of the piece because he refuses to alter his worldview to accommodate Rory's wish save the older version of Amy.
Five Kills Kamelion
Arguably the most unassuming incarnation of the Doctor, Five was subject to a great deal of tragedy during his time in the TARDIS, ranging from the death of Adric to the massacre of Silurians in "Warrior's Deep" to Tegan's tearful departure. Despite the weight of the world bearing down on the Fifth Doctor, he largely maintained his snarky yet chipper composure.
Some have questioned the Fifth Doctor's status as the nice Doctor, with Poseidome quick to point out that it was quite weird that he showed "no remorse" after killing Kamelion. Even though the action was one which Kamelion begged the Doctor to carry out because he was already dying, his weird behavior following the act doesn't do Five any favors.
The Tenth Doctor Condemns The Family Of Blood To Eternal Torture
"The Family Of Blood" is generally considered one of the best episodes of Doctor Who from the Russel T. Davies era. It's full of emotion, scares, and Martha taking initiative. It also features one of the darkest villain fates in Doctor Who history.
Redditor lukeyflukey got right to the controversy of "The Family Of Blood's" ending by calling out the Doctor's choice to condemn "4 beings who were prisoners to an eternity of torture" as cruel. It's a shocking moment and one that jars with the perception of the Tenth Doctor as a person who sees the best in humanity.
The Seventh Doctor's Emotional Manipulation
Easily the darkest incarnation of the Doctor, Sylvester McCoy's portrayal of the renegade time lord took the scheming buffoonery of the character to a whole new level. He didn't bumble into situations like previous incarnations, instead seeking out evil and choosing to stamp it out prematurely.
While much can be said for the Doctor's decision to blow up Skaro and talk a Dalek to death in "Remembrance of the Daleks." Redditor Morhek found the most loathsome action the Seventh Doctor took was "destroying her faith in him to defeat Fenric" in "The Curse of Fenric." Without hesitation, the Seventh Doctor broke his friend's spirit in a wild gambit to save the Earth and though he apologized afterward, he continued to manipulate Ace.