A crucial difference between Star Trek: Deep Space Nine and other Star Trek series is DS9 allowed its plethora of characters to have serious romantic relationships. This is an important distinction that separated DS9 from other Star Trek series, and it was a prime catalyst for the intense loyalty DS9 fans feel towards Captain Benjamin Sisko (Avery Brooks) and his space station's expansive cast of characters. Sisko himself, already a widower and a single father raising his son Jake (Cirroc Lofton), broke the Star Trek Captain's mold by falling in love and marrying Captain Kasidy Yates (Penny Johnson).
Romance wasn't reserved for Captain Sisko on Star Trek: Deep Space Nine as many of the characters found love during its 7 seasons. Odo's (Rene Auberjonois) unrequited love for Colonel Kira Nerys (Nana Visitor) was rewarded with a relationship. Worf (Michael Dorn) and Jadzia Dax (Terry Farrell) fell in love and married before Dax's tragic murder. Rom (Max Grodénchik) got the Dabo Girl of his dreams when he married Leeta (Chase Masterson). Of course, Chief Miles O'Brien (Colm Meaney) was already happily married to Keiko (Rosalind Chao), and they had two children. Bizarrely, even Gul Dukat (Marc Alaimo) and Kai Winn (Louise Fletcher) had an unholy love affair. Overall, there was more steady romance on DS9 than Star Trek: The Original Series, The Next Generation, Voyager, and Enterprise combined.
Why Star Trek Couldn't Have Serious Relationships Until DS9
DS9 was the only one of the first five Star Trek series that wasn't centered on a starship exploring strange new worlds. Star Trek: The Original Series set a very 1960s standard of Captain Kirk (William Shatner) as an adventure hero whose first loyalty was to the Starship Enterprise and his crew, and the other Star Trek series followed suit for better or worse. Kirk had affairs in TOS, but his one true love was the Enterprise. Captain Picard (Patrick Stewart) continued this trope on TNG, while Captain Janeway (Kate Mulgrew) had to devote her energies to getting the USS Voyager home from the Delta Quadrant, so any romance had to take a back seat, to the chagrin of fans who shipped Janeway and Chakotay (Robert Beltran).
There were certainly relationships in other Star Trek shows besides DS9. On Star Trek: Voyager, Lt. Tom Paris (Robert Duncan McNeil) and Chief Engineer B'Elanna Torres (Roxann Dawson) fell in love while Lt. Chakotay also got involved with Seven of Nine (Jeri Ryan). T'Pol (Jolene Blalock) and Trip Tucker (Connor Trinneer) had a romance on Star Trek: Enterprise. But relationships were few and far between on Star Trek: The Next Generation, and the series' most famed lovers, Commander Will Riker (Jonathan Frakes) and Counselor Deanna Troi (Marina Sirtis) remained platonic for all of TNG's 7 seasons before finally marrying in Star Trek: Nemesis. Yet DS9's love stories were richer, plentiful, and more complex.
Discovery Is Following DS9's Relationship Model
Star Trek: Discovery is the spiritual successor to Star Trek: Deep Space Nine, and not just because Disco is heavily serialized, which DS9 pioneered in the 1990s. DS9's characters didn't seek out new lifeforms, but they journeyed within to better understand themselves. In turn, Sisko, Dax, Worf, and even the ancillary guest stars were self-aware characters who were capable of complex, emotional relationships. Star Trek: Discovery may be set on a starship, but Captain Michael Burnham (Sonequa Martin-Green) and her crew also explore heightened jubilations and intense emotions in their relationships with each other.
Michael Burnham and Cleveland Booker (David Ajala) are Star Trek: Discovery's central love story, and they are as emotionally mature and heartfelt as Sisko and Kasidy, who trail blazed two Black Star Trek lead characters in love on DS9. Discovery also boasts Dr. Hugh Culber (Wilson Cruz) and Commander Paul Stamets (Anthony Rapp), Star Trek's first gay couple, who are 100% in love and committed to each other. Even Captain Saru (Doug Jones) has a developing love affair with President T'Rina (Tara Rosling). Love, with all of its joys and challenges, is perpetually in the air on Star Trek: Discovery in a way Star Trek hasn't enjoyed since Star Trek: Deep Space Nine.