The biggest reason you see so many Can Ams and Polaris's on the lid and crashed is simple......
There are so many.
Sit out at the Swingset and 90% of the Side by Sides are either Rzr's or X-3's . So naturally they are going to seem to be over driven the most because they are driven the most. Add to that that Can-am and Polaris make it easy to sign and drive for anybody who has a pulse.
Sit out in the dunes on a ridge between any of the destination points and you would be shocked at the number of groups who have no idea what so ever how to dune. They straight line up and over, up and down because the GPS is telling them there destination is 1/4 mile directly in front of them. I have actually seen a group of 5 cars transition over a dune go to the bottom of the bowl, diamond the bottom of the bowl go up and straight over the other side 20 feet away from where the first guy transitioned . It's laughable and scary at the same time.
Once the Speed Car is out there I am going to guess you will see more Yamaha YXZ's in a weekend then you will Speed cars, Hell even if every Speed owner was out in the dunes on one weekend. There still wouldn't seem like there are that many. Add to that like I said earlier they will be driven by the guy's who think they are Robby but at least know they are not. Oh they will push them hard I am sure and some will end up on the lid but it won't be because of a rookie driver.