I wonder about the rules changes that tilt the game toward passing. Pass plays seem to produce the biggest hits as receivers get nailed and as the quarterback occasionally gets blind-sided. Additionally, the rules that force DBs to lay off WRs means that the best way to break up a play is to put a safety in the path of the receiver to blow him up. With bump and run coverage you probably won't get as many brutal hits.
So the NFL seems to think that passing plays are marketing gold. But what if those plays cause more injuries? Should we go back to the rules of the 1950s?