Earlier quoted context omitted.
I don't think it really is - drive-by changes have been a net burden on maintainers long before LLMs started writing code. Someone who wants to put in the work to become a repeat contributor to a project is a different story.
How to differentiate between a drive-by contribution and a first contribution from a potentially long-time contrubutor. And I would say especially for operating systems if it gets any adoption irregular contributions are pretty legit. E.g. when someone wants just one specific piece of hardware supported that no one else has or needs without being employed by the vendor.
Potential long time contributor is somebody who was already asking annoying questions in the irc channel for a few months and helped with other stuff before shooting off th e PR. If the PR is the first time you hear from a person -- that's pretty drive-by ish.