I think OP is saying that github, and forges like it, making pull requests so easy, have created a situation where the users bother them too much with said requests. This wasn't always the case with open source, back before community web-based forges were a thing, and it was much more difficult to collaborate from outside the project (where the project has their own regular contributors that do most of the work).

But I don't think most people actually want to just turn off pull requests like they are suggesting... I think that would be disastrous for the open source community as it operates now, and may push people further away to other (maybe even closed) projects.