Adoption of unmaintained packages to maintain them is not a mistake. The problem is the current implementation, not the idea behind it. It's like saying the AUR is a mistake, because some people do malicious stuff.
They should find a better solution, like adoption shouldn't be granted to everyone without question, especially new accounts who didn't maintain anything before. Mass adoption shouldn't be granted automatically (limit rate), in example 1 package adoption per day and if someone wants more, admins or moderators need to approve. And updates of newly adopted packages should wait a day.
Also the AUR helpers should do a better job. Always ask if a new adopted package should be updated and give a warning the maintainer changed.
Adoptions are a mistake anyways. Remove unmaintained packages and block the name for several months.
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