Calvin27
Eats Squid
Objectively what you've written is "true", but if you even scratch the surface it's clearly not realistic. Yes, "anyone" can "just pick up a bike" and "start riding off road", but that actually still relies on a few key assumptions, and also doesn't accurately describe what really any of us would consider to be the world of MTB that we seek to share.
Back to what I said about cost being the key factor. When I was a kid everyone at lysterfield rode BSO (had a bigW huffy myself) on the trails. A beginner could take almost any bike out and start riding for relatively cheap, but if they truly commit to the sport (like most of us here) then it's a steep cost curve. Soon you are paying for forks that cost twice as much as your first bicycle. It's this normalization that really starts filtering out the regulars.