> you don't have a marketing budget either, so your app won't make money
There are ways to make money without buying ads. A friend and I grew a small company in our teens to roughly 6k monthly revenue by just posting on forums. That's a lot for students who still go to school. (We were coding cheats for video games)
I'm certain you can do the same with apps, if you find the correct niche.
Are they, though? If you don't have the $99 for a dev account, you don't have a marketing budget either, so your app won't make money, so Apple doesn't care.
I think the best argument to be made for catering to hobbyists is to attract new developers to the platform, but I doubt Apple cares about that any more. Apple wants developers who care about making money. Developers who care about making money will come to Apple because of how much Apple users spend on apps.