There’s no doubt in my mind that it’s intentional gatekeeping. There’s a reason why many papers are being “published” on Arxiv and foregoing all this boxticking.
The whole publishing process is fundamentally broken. Aaron Swartz (RIP) had the right idea all along. Get rid of the middlemen sucking up millions of dollars by paywalling government funded research.
It’s been proven time and time again that a shocking number of studies can’t be reproduced and that the traditional peer review process just isn’t working. It’s a good old boys’ club putting a stamp of approval on their friends’ work and keeping the outsiders away.
When it comes to Math though, I do have some sympathies. There are so many cranks that think they solved Collatz or a millennium problem and don’t even know what they don’t know. It must be exhausting to sift through all that noise in a volunteer, unpaid position. These shibboleths might be a necessary evil.