Three wheelers are the reason that they came out with four wheelers. I'd ridden street and dirt bikes my whole life and a buddy let me ride his Big Red three wheeler. Painful lesson #1: Do not put your foot down off the pegs going around a corner. Lesson #2: Do not lean where you want the bike to go. There was one pine tree in an entire field where I was riding and it was like that tree was reeling me right toward and into it. Entirely different skill set than a bike or four wheel ATV. People that had them could really ride them and that wasn't me, and most people evidently or they would still be available. I remember reading about them when they first came out. Dirt Bike Magazine called them cute, but not very practical.
Isn't that the truth. We spent the last 3 days in the hills with our SXS. On rocky trails, it's hard enough to find 2 tracks for the tires. Finding 3 tracks would be impossible. They don't straddle rocks, they have to bounce over them.