Ahhh, but there's the trick. For a proper block-up (and pushup, dip, etc.) you have to stabilize your torso against gravity, much like a vault (or any other natural movement). For a bench press, on the other hand, you are stabilized against the bench. How many real-world situations require you to push against force at a perfect 90 degree angle to your torso while on your back?
Once again, the bench press has its place, but it is by not means a worthy movement by which to gauge the absolute or relative strength of an individual. On the same token, it would be a poor movement on which to base a fitness program aimed at increasing functional performance.