I didn't actually hate Nemesis it was an OK movie, it was certainly bigger scale than Insurrection or Generations but it felt as though the script needed one more tight draft. Now, I learned something interesting a few years ago I was at a panel with Brent Spiner and Marina Sirtis and they mentioned that there was something like 4 drafts of Nemesis written by Logan. Spiner, Stewart and Logan liked the 4th draft because it was the tightest and more epic and worked out a lot of the kinks from earlier drafts, however, for whatever reason Rick Berman decided to go with an earlier draft of the script. Spiner mentioned the 4th draft didn't have the B4 element and the ending of the movie was more complex and Data's death bigger. It was likely costs related that Berman decided to go with the smaller version.
Nemesis tanked at the box office for a number of reasons. It had a bad release date pitted against two of the biggest movies of the year. Also at the time I think a lot of fans were upset with the franchise as a whole. Quality of Trek had been on the decline for the last few seasons of Voyager and Enterprise and I think there was burn out and hostile attitude towards Berman. I remember negative fan reaction to the movie online months before it even came out!
I've always been sad that this is the way TNG went out. I felt as though there was one last TNG story to be told. The Undiscovered Country of TNG if you will.
I think the state of the franchise and the lack of effective marketing had more to do with the box-office performance than the release date. After all, it was only released against "Maid in Manhattan" in its opening week and it still lost to it.