I appreciate where you’re coming from, I appreciate the distinctions that you’re trying to draw, but…this is not a good plan, folks, you will not like the thing it ends up doing.
As long as we’re careful to specify that this doesn’t just mean someone who’s socially awkward or “creepy”
That never ever works. Once you create a discursive category, it will immediately start mutating to fit the needs of the people in the discourse. Once you create a discursive category that is specifically crafted to be an insult, it will immediately start being used to insult whatever groups people actually want to insult, so long as they’re close enough to the blast radius that the semantic stretch can be made to work. That is how categorical language works. And if you try to push against it, to defend the rigorous boundaries of your terminology…well, we’ve all seen how well the phrase “well, actually” fares in the wild.
“Grognard” sounds a whole lot like it means “filthy basement-dwelling subhuman autistic neckbeard.” Therefore, if it gains any traction, it will be used to mean that thing by the many people who are invested in making such attacks. The niceties of your usage choices won’t have any power to constrain.
To be clear: I don’t mean to be policing your private vocabulary here, it sucks when you can’t talk as you please, use whatever terminology makes you happy (and live with the consequences if/when people misunderstand you or diverge from your intentions). But it sounds like you’re saying that it would be good to make a public campaign of spreading this particular usage of “grognard,” so as a member of the public I’m pushing back.
The best results are likely to come from not creating weaponizable categories. Say the thing you mean, don’t chunk ideas together. You want to say that someone is complaining about other people having Bad Wrong Fun? Say “he’s complaining about people having Bad Wrong Fun, and he should stop.” It’s more words than “grognard,” but the costs are much lower.