It's true that being under 25 doesn't make you a bad driver, or being over 25 makes you a good driver...
It is based on attitude an skill.
However, a majority of under 25 yr old males have less respect for things in general (especially when they did not earn them) and have less experience behind the wheel.
So, While there are exceptions to the rule (as every young person claims they are), there is a higher risk of injury. Stats don't lie.
All I know is, you young guys who have had 5+ cars and now have an NSX, you better respect the hell out of that car. I've had one car ever, $3500, (I'm 22) and won't have an NSX for a very long time ($90K+ in student loans). I don't know how you manage to buy sportscars, but however you are blessed (you have to be to buy one so young), you better respect the hell out of it. I'd kill for an NSX.