I think a lot of OT fans in particular view RotJ as the point when the franchise started to tip in a direction they didn’t like, with George apparently exerting a greater degree of creative control and leaving less room for collaboration. Some say that it marked the beginning of George “selling out.” Often, people back this up with comments from Gary Kurtz or Lawrence Kasdan, who were both clearly unhappy with the direction taken in the story, wanting a more downer ending that challenged the audience. George wanted a more clear-cut happy ending, of course, and I think that was the right call in the long run.
I would say “a few OT fans” rather than “a lot of OT fans”.