too much money can also (and unfortunately often does) demotivate creators. After releasing one or two updates that weren't huge, they didn't notice a drop in revenue, so they make another one that's not as "productive" as they could have, and the money continues to flow. Of course, we're not talking about you, but there are many such creators.
I think you're misinterpreting the situation with these creators/developers.
Supporters notice that the developer has stopped working, and developers who do this, all of them eventually lose everything they've built.
Some supporters notice immediately, others hold on, hoping for work to resume, but eventually, everyone notices.
I doubt it's money that demotivates them, that's never been my experience. When you pay people more, they work harder. That's almost always the result of good pay. Losing good pay means losing a lot, so people make sure they perform.
And the people who can't perform at that level, they lose the money, they lose the job . . .
When you see people lose good jobs, it's often personal problems, drug use or inability to handle pressure -- and they blow themselves up, all their future gone. You see this happen at university too. People work hard to get into a good university (and pursing a degree that will lead to jobs), then blow themselves up when on their own on campus, can't handle the pressure, can't handle independence responsibly.
That's what we're seeing with some of these developers.
It's not the money that "ruins" them. They have other problems; demons in their life.
Or . . . . they just can't do it.
Like you said, a developer starts with a big bang, and supporters think the developer can continue at that high level of performance, so they fund him, he's happy with the money, and tries to continue, but can't maintain that high level of performance, regresses to the mean, and fails.
One hit wonders in game development.
Same as one hit wonders in music.
These musicians aren't lazy, they aren't demotivated by the money they got for their one hit. They don't WANT to have only one hit. They try to get the second hit. But they just can't maintain that high level of performance.