If you're making a PR to my repository, I would like to be in control of whether my repository's resources are used for your PR or not. It doesn't matter whether you've had your account for 10 minutes or 10 years.

(And they certainly are "my repository's resources", since the build machines pool is shared between workflow runs for branches and PRs.)

They're codifying what a lot of repositories do with bots today anyway, where a maintainer triggers the CI to run on a PR by posting a comment.

Also I'm confused how you can simultaneously berate them for not building a user reputation system, and then berate them for hypothetically building a user reputation system.