IME means" in my experience". And having spent a significant amount of my life in toxic environments like food service, construction, and landscaping, my experience is that it is used far more as an insult than self referential.
But, that’s real life, which some may argue is even more important than online, but doesn’t come with as easy citing and annotation.
So, yes, I carefully did not disclose my relationship status among co-workers, as either they would want to take me out to the club or bar and “get me laid”, or they would become insulting over the fact that I couldn’t.
I found that letting people assume I was gay was far preferable than admitting that I leaned towards heterosexuality, but just didn’t get on romantically with women.
Now, I probably felt some level of bitterness about this, but it wasn’t about not dating, it was about the social pressures that if I wasn’t dating, something was wrong with me. I was perfectly fine on my own, and while I’m not the most experienced in the world, I have had sex, and to be honest, I kinda prefer my own cooking.
In the end, I do think that some people who are just perpetually single get pushed towards incel communities by social pressure. They are told that something is wrong with them, and so the seek out peers who won’t tell them that there is something wrong with them. It’s not the healthiest validation out there, but people do tend to group up with people who validate their feelings, rather than insult them.
As I said, he can speak for himself, but I see it as the exact opposite, in that those in this thread are talking about the dictionary definition, and he is talking about how it is actually used in the real world. You are trying to say that it only refers to this particular group of people, with these specific traits, and that may be the accurate use of it, but it gets used against far more people, anyone who demonstrates any of the traits.