I completely understand your frustration. I've been with C2 for about 4 years, always working with CJS. It's had it's ups and downs but I always stuck with it and tried to just work around issues. Cocoon.IO has come a long way and I believe is truly a more professional compiler than CJS was, which is why it's no longer free. $500 per splash screen removal may seem like a lot, but like you said, for professional products, it's not that big of a deal.
Game Maker does not make you pay for splash removal, but has a much higher price tag up front. Which I would gladly pay as well.
C2 is an HTML5 engine. That's it. By being that, it has the ability to run on multiple platforms as well, with some work and help of 3rd party vendors. Making games and publishing on multiple platforms has never been easier, but it's still hard work.
Think about how often Android and iOS update their OSes as well. Getting everything working together takes work and dedication .