Oh I dunno, I kinda felt the opposite. I thought a lot of people were willing to forgive the flaws because they'd invested so much time into it (I was one of them). And the final season was really rushed. It really should have gone on for another season, because what should have been a slow descent into madness for me came across as a spur-of-the-moment hissy fit. Jon coming back to life was a problem too, because it then removed all trepidation for his character from that point on. Whenever he was in danger (in the battle scene a few episodes later) you knew he'd survive because they wouldn't bring him back to life just to kill him off in the next few episodes.
For me The Two Towers was by far the best LOTR film.