Mtb is fun, you don't have to ride trails that would contribute to you falling, Mtb is no more dangerous than road biking. for me Mtb is like doing a road bike but out in a forest. I love it and I've been contemplating a new Mtb instead of a new road bike. I just returned from southern Colorado where I spent 18 days hiking and Mtb riding my longest day was 5.5 hours for 20 miles it was absolutely incredible. can't wait to go back.
I love riding any style of riding but I also sold my hybrid as I just found that I never rode it really. I only Mtb once or twice a month and I do about 250 to 500 per month on my road bike. Mtb miles are completely different short miles equal tough workouts. road biking you get into a rhythm and can go as far I want to. Mtb riding can be about lots of things but it's really great to be out in nature.