If you run the wishbone, I agree. If you spread the ball, it helps with timing, efficiency, progression, etc...I have been doing 7 v 7 for a long time and have NOT seen an injury at a 7 on 7. However, I have seen injuries in the weightroom...should teams stop that too? Heck, I have seen kids roll ankles getting out of their cars. IMO it's worth the "risk" if it gets you better.