i admit that i have only a PVE perspective on this things, i don't do much pvp. I wage that all the actual pve content can be done without pushing that button even once.
And since blizzard want to homogenize the tanking, and other class does not have anything that comme close to it (except may be DK), this will not change et the use of that spell reflect will be, at best, anecdotic.
So yes, in the mostly pve talent tree, i would suggest a modifier to make the spell more useful in PVE.
On a RP perspective, i really like the spell, and i can see how a warrior would take cover to deflect a dragon breath or a direct spell, it's feel too bad that that spell is currently abandonned in PVE