I've heard the Crowdfunding rules mainly exist due to the Japanese not liking crowdfunding hence it not being being allowed, as they view it almost as investment and making money before the work is made, combine that with the fact issues can arise from it, the one that comes to find is FNF which is in development hell, and I can honestly see why it's not allowed, though mostly neutral on that issue, though it might be nice to get more out there. For the mobile games should one want to make one you could just make it free with ads and pay to remove them, which is what a fair few games on mobile do anyway.