Star Trek: Enterprise's finale, "These are the Voyages...," is probably the least-liked of all Star Trek intentional finales. I say intentional because Star Trek: The Original Series ended with "Turnabout Intruder," which wasn't set up to be a series finale. Since Enterprise ended in 2005, the finale has been villified, and most Star Trek fans refuse to watch it. That makes sense. If you dislike the episode, you dislike the episode. And most people wonder what the producers were thinking to have the series go out on a note like that.
In an interview with CinemaBlend, John Billingsley, who played Dr. Phlox on Enterprise, looked at the finale from a different point of view. While it was supposed to wrap up the series, many of the crew that had been working on Enterprise had also been working on Star Trek since The Next Generation. So they had a seventeen-year history with the franchise that was coming to an end.
"I mean, it was weird when we wrapped that final episode. It was poignant for us as a cast, but we'd only been on the show for four years. The crew had been there since the first days of Next Gen. That crew had transitioned into Deep Space into Voyager and then into our show. So, for many of those folks, it was the end of seventeen to eighteen years of their lives, watching their kids grow up, marriages, divorces, deaths. It felt like the end of an era as much as anything because that group of people broke up. And if you're in the business, so much of what, you know, makes it feel familial is when you were hanging with the same crowd for an extended period of time. That was where I think it really, for a lot of folks who were associated with legacy Trek, that's where I think it really felt like, you know, the ax cut."John Billingsley
Billingsley points out that the cast of Enterprise only had four years so it wasn't the end of an era as it was with the long-term crew. So while Enterprise had to wrap up, the producers chose to introduce other characters that encapsulated the entire history of this era of Trek. In that way, it also paid tribute to the crew members who had spent a good portion of their lives behind-the-scenes with Star Trek.
This won't make fans like "These are the Voyages..." any better, but it does, at least help to explain why the producers chose to go that route rather than focus on the cast of the Enterprise...even if we don't agree with their decision.