They might’ve had one (or several) bad experiences and this is a trauma response, but even in that case, I don’t think it’s unreasonable to say “yeah sure they’ll pay their own way, I just feel safer if we have a second pair of eyes I trust in the restaurant/cafe/etc with us”. Like, you don’t gotta be at the table, but I kinda get it for the first date or two being “hey I trust this person, mind if they tag along and grab a drink at the bar to be my watchman or whatever”.