Not quite sure what the issue is with the lack of helmet. Most of all, a helmet is a personal choice. "Whatever" if the OP doesn't want to wear one. And it's not like that was particularly helmet worthy riding/terrain anyway. I might not have either. I never do on my 1mi commute to work on untrafficed roads. Maybe find a video of someone on some real trails with some nice sharp, or at least plentiful/large rocks and whine about them not wearing a helmet.

Not cool riding on trails that clearly aren't riding trails, though. Find some MTB trails to ride. If nothing else, OP, you're giving bikers everywhere a bad name. Glad you crashed(though didn't get seriously injured).