According to Joel Hodgson, the riffs in season one were fully scripted, but they were nervous about how many they could put in, worrying that they would distract the viewer from the movie and therefore ruining the context of some of the more plot focused riffs. And though Weinstein wasn’t a big fan of having to watch the movies over and over again (as per the writing process), the real reason he left is that Jim Mallon used his youth as an excuse to stiff him financially. When the Comedy Channel deal was made and Best Brains was founded, Hodgson and Mallon both had 45% ownership over the show, with Trace Beaulieu and Kevin Murphy each having 5%, meaning that Weinstein was the only founding member of MST3K who had no ownership stake. Apparently this was because Weinstein was not legally able to participate since he was only 17. But it also turned out that he was getting paid less than the secretary that was hired. When he confronted Jim Mallon about it, he was essentially told he should just be grateful that he was along for the ride.