It often is. The concept of "gatekeeping" becoming well known and something people blindly rail against was a huge mistake. Not everything is for everyone, and "gatekeeping" is usually just maintaining standards.

Ideally the standard would just be someone's genuine interest in a project or a hobby. In the past, taking the effort to write code often was sufficient proof of that.

AI agent coding has introduced to writing software a sort of interaction like what brands have been doing to social media.

I think the word you're looking for is curation. Which people who don't pass jury might call gatekeeping.

I'm not sure what distinction you're trying to make, but it seems like you might be distinguishing between keeping out substandard work versus keeping out the submitters.

In which case, I kinda disagree. Substandard work is typically submitted by people who don't "get it" and thus either don't understand the standard for work or don't care about meeting it. Either way, any future submission is highly likely to fail the standard again and waste evaluation time.

Of course, there's typically a long tail of people who submit one work to a collection and don't even bother to stick around long enough to see how the community reacts to that work. But those people, almost definitionally, aren't going to complain about being "gatekept" when the work is rejected.