that's quite the charge there, somewhat insulting and offensive but hey, to each his own!
Sorry to offend, but I'm guessing that you guys can take it. Opinions will always vary, but it never hurts to think about it.
One opinion:
"Know that the American Academy of Pediatrics recommends that children under 16 years of age should not be permitted to drive a snowmobile, and children under 6 should not even be passengers. Smaller snowmobiles designed for children aren't any safer, as it doesn't change the fact that children still have undeveloped motor skills and field of vision capabilities as compared to an adult."
Read more: http://www.ehow.com/how_2098904_snowmobile-children.html#ixzz2jaVGFP3R
Another opinion:
"In case you haven’t guessed what I think about this yet, I think it is crap. I think that for a few reasons. The first of which is my parental rights being decided by another. Aside from beating my children and other reasonable leglities, I don’t like that. I don’t like it when other peple tell me how my kids should be raised. Especially people that know little to nothing about my lifestyle. However, I’ve got better reasons, too. I believe that when you start kids young and teach them well they learn well. They learn how to enjoy a sport like snowmobiling and they learn from a responsible adult how to do it safely. At age five my child will listen to me. At age 16 that same child, placed with a high-horsepower sled under his thumb for the first time, will nod impatiently and gun the throttle. Lessons be damned. Kids learn better at an early age. They have more respect for teachers and parents at an early age. And they have more fear of getting hurt. This is somehting you can capitalize on when kids start riding and respecting the ride from a young age. But it’s a window of opportunity that is missed by the time they are teenagers."-

I tend to at least consider the thoughts of the medical community on the issue because they are the ones that have to deal with the carnage that can result from accidents.
My hidden top secret agenda in all of this is to stimulate people to at least think about safety issues from time to time, and hopefully make riding better for everyone. I tend to think that there is always room for improvement, but there will always be those that will insist that the sport has to be a total "free for all" out there.
There are always risks out there, but these high performance extremely heavy weight "toys" are a relatively new phenomenon.