I have tried to reserve judgement for years. And to date, I have yet to see a single one of them signal how many are in their convoy or employ right-of-way etiquette. At the same time, the overwhelming majority are either dusting other passers-by, riding off trail, speeding excessively, cutting the apex off blind corners, etc. etc.
I was in Stevens Canyon/Beef Basin halfway between Moab and Monticello in the middle of absolutely nowhere early last year. A group of side by siders roll up with a Moab city road map and ask for directions because they didn't know where they were at. They had no gazeteers, no compass, no GPS, no land navigation equipment of any kind, and were out zipping around 90 minutes from the nearest emergency responders without provisions. They then tried to pass one of my guys doing an active recovery 'cause they couldn't be bothered to wait, and nearly drove through a winch line that was tensioned. It was the perfect embodiment of every side by sider I've ever seen.
It's a big, dangerous "toy" that people with zero expertise or ability take out with no training or regard.