a show with such fantastic writing ends with such a contrived pile of garbage - why?!?!
While there were certain aspects of the finale I did not like, I would hardly call it a "contrived pile of garbage." However, unlike your vague generalization, I will list the things I didn't like.
1. I really did not like the reuse of battle footage from a previous episode for the "final battle." I felt it was an incredibly cheap move, especially for the series finale.
2. The whole "Sisko abruptly leaving to go die in a fire cave with Dukat" thing was totally contrived. If they spent more time on that scene, it might have worked better, but it felt like it was just thrown in at the last minute.
3. Damar's death was also very contrived.
Other than those three points, the finale was just fine.
Wasn't it about the creation of the Coalition of Planets, I do seem to recall they made an episode of TNG set on the holodeck of the Ent-D with a recreation of events circa 2161 called "These are the Voyages" after this story however.
That is actually quite funny.