Part of it might not be because crush is a scam artist or a bad person intentionally. Humans easily take things for granted and that doesn't mean they are bad people, it means they are human. When you have a steady flow of patreon support/money you can end up taking that for granted. People are supporting, they like you, like the game, so instead of starting bangkok; crush might think "maybe i can tinker with the sex engine and make it even better." If this works, then the pay off is great, but if it doesn't work it delays the game and pisses off a lot of people. Unfortunately for crush it didn't work fully, and he started having problems integrating it with the story/scenes.
There are many reasons crush wanted to work on the back end. The most notable being that if you write tons of story then later work on the back end, you have to go through ALL that story you wrote and make changes, which is a shit ton of work. VS having very little story written so when you work on the back end the changes are faster to apply to the story.
That being said... i also think some people have different view of patreon - including me. It's not paying for an end product. I am not losing my life savings to crush. I view it as instead of buying a coffee at starbucks once a week i decided to give the cost of that coffee to crush once a month. I don't have to do this. I can stop at any time. But I do this because I support him and the idea for the game, not because I want story content every month with my coffee. It's not a trade... it's not here is a coffee and give me story back. It's here is the cost of a coffee and hope you make a kick ass game!
Anyway, probably everyone will be pissed that I don't think what crush did was intentional. I just think he got carried away and excited about making the game in his vision and took for granted that people were giving him the cost of their coffee every month. If patreon was under the premise that these are everyone's life savings, i don't think he would have so readily taken that for granted.