All of those were also all $0–$20. It's kind of a chicken and egg problem to build a user and developer community. Games have to build a strong playerbase with limited content, then enough gamers have to be invested enough to become creators. Enough have to be able to actually pull off the development, yes, but I think the even bigger problem is that they'll never have a reason to with the small number of users inherent with platforms that cost $500–$3500 for special hardware to get onto.