It is the responsibility of the person running the coding agent to make sure the resulting PRs are high quality. Putting that on your team mates, or worse, random open source project maintainers on the internet, is the definition of an extractive contribution.
And
> he's proposing a method for how to do so using agents
Are not in agreement. The claim being made is that you shouldn't be sending PRs you haven't personally vetted to be high quality. Definitionally a bot cannot be used to personally vet something.
As a software developer, you must never subject your team mates to a PR that you yourself believe to be low quality. The point of code review by others is to catch things that you missed.
There are multiple lines of defense for quality. Yes, automation can and should be one of them, but your own self-review always has to come before review by your team mates.
However, from an operations perspective, a dev is a piece of the qa pipeline with a nonzero error rate, and an optimal throughput rate, above which that error rate rises dramatically.
As a dev, you'll never merge a bad PR; in ops, we want to help you with that goal, and also have plans for what happens when it fails.
Put another way, who are they supposed to hire to tell these low quality PRs apart from the high quality ones? Who even knows how to do something like that?!