Are you dense?
It's unfortunate for users, rational beings who, having spent several hundred/thousand dollars on pro applications, can generally expect not to be served malware. I don't really need Apple's assistance to ensure that Ableton doesn't sell me a trojan. If they do, I have my lawyer's number in my phone, we know who to sue, we've got it covered. It's unfortunate that the way the rules are currently written, no pro media application will be able to take advantage of iCloud functionality…except of course the ones that Apple sells.
I don't care who Apple trusts. And if the answer to "Who does Apple trust?" is "No one but Apple," that says more negative things about Apple than it does about the tens of thousands of software developers, large and small, who aren't Apple.