In Grey's Anatomy season 17, fans were treated to the return of Dr. Derek Shepherd (Patrick Dempsey), who was tragically killed off in season 11 — his return to the show, however, was a huge mistake.
Derek Shepherd, known by many of his colleagues as "McDreamy", was a main cast member on the ABC medical drama since its inception in 2005 until his departure. His relationship with Dr. Meredith Grey (Ellen Pompeo) was a focal point of the series. Throughout the show, the couple went from dating to married to starting a family of their own. While they had their trials and tribulations, just like every major couple on Grey's Anatomy, it seemed that they were "MFEO", which means "made for each other" a term that many fans of the show have adopted for their favorite couples who, they assume, will last forever. However, that's not always the case, as many other seemingly long-lasting couples have been split apart by divorce, separation (both permanent and temporary), and even death of one or both people.
Derek was killed after being struck by a car in Grey's Anatomy season 11. He didn't die at the scene of the accident, but later succumbed to his injuries after being taken to a hospital that lacked the wealth of resources Grey-Sloan Memorial Hospital has. This was ultimately what led to his demise — Derek developed a head injury that, ironically, could likely have been repaired by Shepherd himself under different circumstances. His reappearance in the two-part season 17 premiere, "All Tomorrow's Parties/The Center Won't Hold", happened as part of a "dream" sequence that transpired after Meredith collapsed in the hospital parking lot. This was intended to foreshadow Meredith's battle with an unforeseen illness — the COVID-19 virus. Grey's Anatomy season 17 chose to make the ongoing COVID-19 pandemic a major part, and Meredith's battle with COVID is meant to highlight the struggle many Americans and their families face. However, the notion of Derek being on a beach calling to her is slightly tone-deaf given the greater implications, and ultimately, a poor decision by the show's writers.
After Derek's tragic death, Meredith saw major accomplishments in her career, though balancing a work life with her family life sans the presence of her husband was difficult. However, Meredith did end up thriving in many ways, especially professionally. In a way, it seemed very much like she was out from Derek's shadow, which was never intentional, but always an ongoing theme—and sometimes a point of conflict—for the couple. Meredith, in time, opened herself up to the possibility of new loves, including fellow surgeon Dr. Andrew DeLuca (Giacomo Gianniotti). This, in true Grey's Anatomy fashion, became a love triangle when Meredith caught the eye of yet another surgeon at Grey-Sloan, Dr. Cormac Hayes (Richard Flood), a pediatric surgeon.
While Meredith will never forget Derek, it's clear by Grey's Anatomy season 17 that she has, at least to the extent anyone is able to find closure in such a circumstance, moved on. This makes Derek's reappearance even more suspect, since she's got not only one, but two prospective suitors on the other side, not to mention friends and family. The concept of seeing lost loved ones has been played with before to some extent, such as the storyline where Dr. Isobel "Izzie" Stevens (Katherine Heigl) had what she believed to be a full-blown relationship with the ghost of her fiancé, Denny Duquette (Jeffrey Dean Morgan). Izzie seeing and interacting with Denny posthumously was meant to foreshadow her getting cancer. If Meredith joins Derek on the beach, that clearly means she's forsaken everything in her life to be reunited once more with the man she loves.
Physically, the two are separated by a great distance and, over the course of multiple episodes, Meredith tries to get closer, but can't. Derek, predictably, insinuates that the two of them can be together whenever she's ready. Obviously, as a mother to small children, this isn't a good idea, nor is it a good notion to suggest that Meredith would quit fighting just to be with Derek again. Beyond that, while it's nice to see returning cast members on beloved shows, it drags on for too long and serves as little more than a painful reminder of Meredith's loss, which may have an even more profound—and possibly negative—effect on her in future episodes of Grey's Anatomy.