Are there any famous cases of directors, producers, actors, etc. who have tried to ruin films? I was just thinking of this because Jeffrey Katzenberg is portrayed in every featurette from the Disney company as money hungry, greedy, only caring about the bottom line, and ruining the visions of other creative voices in the company like Menken, Ashman, Stephen Schwartz, Musker, Clements, and so on, until he went off and started the rival company Dreamworks.

Are there any "villains" in the history of film?

Well, the studio system was one big villain against creativity.

Isn't it the other way around with Kratzenberg?

Also, Algren, "was"?

Haha. Good point, but it was worse back then, right? I mean, they basically just regurgitated the same twelve stories. Producers would take the script off the stack, get it filmed, then put it at the bottom. But sure, today's studio system is also not as creative as, say, indie cinema is, but it's still surely a lot more creative than back in the 40s.

They don't necessarily ruin films but Harvey Weinstein and Scott Rudin are considered two of the most notorious assholes in the entire business these days. For the record, Scott Rudin is an incredible producer. But he's apparently a tyrant and incredibly hard to work for. The movie Swimming With Sharks is loosely based on him.

As for Harvey, there was a period where he was known as "Harvey Scissorhands" because of how much he would butcher films to his liking in the editing room.

Alan Smithee

Though a celebrated director, Otto Preminger was widely considered cruel and tyrannical.

MGM executive/"fixer" Eddie Mannix may fit the bill. He helped the studio's stars avoid charges and scandals, hiding, say, Spencer Tracy's relationship with an underage girl. And a popular conspiracy theory implicates him in the death of original Superman actor George Reeves.

Mel Gibson
Chevy Chase

Hitchcock for Hedren.

Marlon Brando and Bernardo Bertolucci, it seems.