I don't really know what incident you are speaking about, so it's difficult for me to respond.
I will say this. I have been published for 60 years. I do not mean in school magazines. I mean in newspapers, magazines, and I've worked for companies as a writer (articles) and in SEO. I've also been an editor for two publishing houses in London, and as a freelance writer on the web, many of my articles have been at the top of Google for a long time.
I have a portfolio of my work (which is very old), but it does show just how long I've been published, and my reviews shows the extent of my accolades.
I get highly the hell in when Medium (which launched as a publication for readers who wanted to read outstanding writing, and about 18 months ago reinvented itself as a 'home for writers.' No professional writer needs support from other writers.
You are right that authors generally call themselves writers. I do. The fact that I've self-published is because I know the industry because I've worked in it (newspapers, magazines, and publishing houses).
I have no desire whatsoever to spend months or years looking for a publisher. I only write for money, and I don't publicize my work or do marketing. I passionately hate marketing. My work is read on occasion, and I sell about 20 books a month. So be it.
Earnings wise, I am probably in the top 1% to 3% of Medium earners. That doesn't say much. Only 5% ever reach $100, and if you make $500 a month (hardly a living wage), you're already in the top 3%,
When someone comments that someone can't write, or that they aren't up to a publishing standard, they are not gatekeeping. They are making a statement of fact. I assume that they have the credentials to be able to say so.
So, can you give me a little more detail (I am interested because I've now twice been accused of trying to be a gatekeeper.)