George Lucas

George Lucas is the creator of Star Wars, Indiana Jones, and several other films.

There isn't an amazing amount of controversy around his part in the Indiana Jones canon, but his position as the creator of Star Wars is a whole other story.

George Lucas wrote and directed the first movie in the classic trilogy (just Star Wars, or A New Hope) but he did not direct the second and third movies (The Empire Strikes Back and Return of the Jedi). Coincidentally, there is a large portion of the fanbase that believe these two movies are the best ones of the run.

These three movies made him incredibly rich and influential. He went on to not take writing or directing aid and create the prequel trilogy. Although the integrity of the prequel trilogy is debated, this act is rather like an influential fiction writer suddenly dismissing their beta or editor... with undebatedly bad results. From a critical perspective, the Prequel trilogy is riddled with problems at the very least-- to the point of being nearly unbearable to some fans. The romantic scenes, in particular, are particularly awful from not only a critical but a simple audience perspective and it is the opinon of many that they should never have seen the light of day.

Secondly, his policy on the Star Wars Expanded Universe is worrying in two different ways--

First, his screening process for letting writers play around in the universe is very loose, and therefore there aren't many books in it which are universally liked (though, inversely, neither are there many which are universally hated, though there does seem to be more bad than good).

Secondly, Lucas has a tendency to ignore the EU outright when assembling new works, which has some sections of the fandom extremely worried. At the worst, speculated Movies 7, 8, and 9 might throw out more beloved bits of the EU and replace them with unsavory and yet very, very canon things. His position on the EU also makes the nature of Star Wars canon confusing; according to him, the films are the only "real" canon, or at the least the films and EU are two different, mutually-exclusive canons. Fans seem to disregard this, but it can make distinguishing what is canon and what is not difficult in the Star Wars continuum.

George Lucas is thirdly notable for being a creator of canon... and also somewhat hated by lovers of that canon. Most of them are thankful for him making it in the first place... but really wish he would leave it alone.