Everything about the film would have been forgivable if Data hadn't been killed off.
Data's death (and the inclusion of B4) does
rather have the feeling of being "one ingredient too many", doesn't it? What Nemesis truly needed to be was a top core political thriller, but all the mucking about, trying to make consessions to Brent Spiner's ego, unfortunately meant that it got weighed down with a subplot that was counter-intuitive to the main plot.
an apologist for Nemesis, though. I don't think there's anything in particular about the movie which couldn't be fixed with a substantive re-edit.
I think the biggest problem is that the movie ended up horribly depressing. Like some bad guy just shot your dog. That's how I walked out of the theater that day, with that feeling.
The movie was standard dumb action flick (one of the lower budget ones), and most of it would have been passable if it had ended on a cheerful note. Having a victorious comeback for Data would have done it. Not the lame "B4 is the new Data" they did.