I just think it's obvious (sorry) flying thru the air (20/ 30/ 50 feet in the air) bike/ rider weight/ speed ...... and then you miss ... which you will at sometime ...... the enertia generated when you "slam" into a jump face ... is going to cause "serious" injuries .... simple physics, really ....
Every injury (of any serious nature) with my family and friends have been from jumps .... ?????