Honestly it runs the gambit. I first was seeing them on cop-related stuff in the 90’s, when everyone wanted to wear black things and look “tacticool.” (go to the 5.11 website if you’re not familiar) I suppose there’s a segment of the population going for “patriotic, yet edgy,” that gets this stuff. As I get older I tend to view these people as looking for someone to fight, but only if they think they can win.
These people usually live in their own conservative bubble, and the behavior is accepted or rewarded. They usually leave the bubble in groups, so they can reinforce their views with each other when confronted or avoided. But when mixing with general society, they tend to mellow out. Leaving an echo chambers does that.
There are definitely people using it as a dog whistle. Those people will double down, not mellow out. These are your idiots attacking the capital. Fuck those guys.