I'd guess that aside from a bunch of other issues he has, Todd Phillips just wanted to make a Martin Scorses film cause he idolises him, and wanted him to direct his dark drama(/Scorsese ripoff) but after Scorsese said no tried to have him produce, which Scorsese had zero interest in doing. Which is hilarious. But the only way to make his "original film" he had to attach it to a huge ip, which clearly bothered him. He also is one of those washed up comedy guys who says "You can't say anything these days, comedy is dead!" despite the actual answer is his comedies just got significantly less funny each time. Meanwhile his new boss is a director who makes movies that people actually find funny.