While I understand your point of view, why let something like this bother you so much? There are a lot of other things that could be addressed when it comes to toxicity in the gaming community. Also, even though you do feel that way, no one is trying to exclude you from gaming by slang words they may use when it comes to a group of people. It comes off like you think these people are attacking you by how they use words and that's simply not the case.
You're thinking about this in terms of intention instead of impact.
People say and do all kinds of things and not intend to hurt someone else. That doesn't mean they don't. Probably in your lifetime you have known people who used homophobic language or derogatory terms for differently-abled people to describe things they don't like. But people have largely stopped using language like this because, regardless of how it is intended, it has a negative impact on the people around them. We now have a different and healthier expectation from others as a result.
The request in this thread is not as severe of a case. This situation is more about courtesy, visibility, and respect. But it's the same idea that people use language they are accustomed without always thinking about how it is perceived. You probably don't mean to be disrespectful. You probably don't mean to exclude women or non-binary people from your conversation. But this is often a side-effect of the language you use whether you intend it to or not.
So if you don't want to do that, why not make the small, free change to make sure you don't?
I'll give you another example that may be more relatable. I used to work with a guy whose older brother was very popular. Everybody called the older brother "Mappy." When the younger brother started getting older and making friends, everybody called him "Mappy Jr". People meant this as a lighthearted joke about him being a popular guy's little brother. But he really hated this nickname because it put him in his older brother's shadow at all times. People wouldn't see him or greet him without implicitly acknowledging that he was somebody else's sibling. It made him feel like people didn't care about who he was, or what he liked, because everybody liked his brother more. He asked people to stop calling him that after a few years, and people felt bad, so they stopped.
What you say and what you do has consequences you may not intend. Something that feels normal and harmless to you might be disrespectful to somebody else. Chances are if someone you knew and liked asked you to stop calling them something, you would. It's not hard to show that same courtesy to others too. You lose nothing by doing it, so why wouldn't you?
