Software development, on Android at least, is already free. It only takes a few clicks to enable third-party apt files, and then you can install software from any source. (And if you complain that this is too complex.. well, it is simpler than many Windows InstallShield wizards at least). You can even install f-droid and then you have appstore experience without a review.

What Google controls is "endorsement" and that's where Google is rejecting things. If you want to reject it, go ahead... but a lot of people actually want it.