Don't self-signed apps expire after a week? You'd need to distribute a new build every week for people to continue to use your app. That's not a major hassle if you're just using your own code, but if you want to distribute something to other people it quickly becomes very problematic.

I agree - for commercial development its a trivial step. But it's yet another barrier to entry for students and people that just want to hack on their own computer at will.

It's also a potentially dangerous first step towards forcing new versions of MacOS to only run code from verified developers - those that pay Apple. Again, trivial for commericial development, but a major issue for non-commercial use.