And look at the ttrpg.network community for a counterexample, they still have a pinned post on the dndmemes subreddit advertising Lemmy and ttrpgmemes gets like .1% of the traffic dndmemes does. And this is still after a months-long rebellion complete with allowing NSFW and restricting submissions to a single user account, both things that would normally kill a subreddit dead.
He says himself that he was there to protect businesses, but he had no relation to the business beyond that of a standard employee, and his help was never requested–he didn’t know the owners, his family didn’t own the business, and he wasn’t even a frequent customer IIRC.
The most charitable interpretation is that an untrained, underage civilian took a semiautomatic rifle across state lines, to a protest happening in a town he didn’t live in, to guard a business that he had no special relation to, and that never asked for his help.
The more probable interpretation, given posts on his social media before the shooting (that weren’t allowed to be shown in court), is that he wanted to play action hero and shoot some scumbags, and he got exactly what he hoped.
EDIT: Apparently he worked at the business he was guarding, but the point still stands–he never got permission to defend the business, nor was it ever offered.