I see all kinds of posts and craigslist ads with RZRs with blown engines (rods, pistons, crankshafts…) or blown transmissions or differentials (cracked casings or bad bearings)

My question is what is the biggest cause of these failures? Poor maintenance, modding too much, or riding style? Guys duning, mudding, rock climbing, racing and jumping?

I mostly trail ride, 2wd and below 40mph on average. 4wd when it snows. I have 1200 miles now and hoping for another 8800k before a major failure.