Yes, lots of people thought disabling package adoption is/was a good idea. It seems quite likely that the Arch DevOps team also could have come up with that one, and they certainly wouldn't have missed all of the people telling them to do so.

It seems to me that disabling package adoption is not a desirable thing to do in general, and can only be used as a stopgap response to an emergency, which seems to be what is happening right now.

"just disable adoption" certainly can't be a long-term solution: Without adoption, the AUR will slowly fade away as orphaning a package would be permanent. Maybe the idea is to have some sort of approval process to filter adoption requests? In that case the AUR just dies instantly as that would effectively be another official repo with all of the issues that that would bring.

Fedora Copr, FreeBSD Ports, are all of a similar idea. Where Arch screws up is in allowing people to take over abandoned PKGBUILDS instead of making them create new ones.

This can happen to Ubuntu with the PPA's too if someone were to gain control over, say, the Nvidia PPA for drivers. It's happening almost daily with NPM and Github. Supply chain attacks are serious and the Arch devs do warn people about this right off the bat. You don't go installing from the AUR without understanding the risks.

Do you have a solution to ever reenabling package adoptions? It's pretty much a must have feature for this to exist long term, at least in the AUR's current state where its a repo your not supposed to auto install from but pretty much all users do.

Really disabling adoptions is probably step 1 to just EOLing the whole thing.

The AUR by definition isn't to be trusted. That's what the official repos are for, you're supposed to read what the package install scripts are doing.