If job gameplay decisions were based on whichever job "got there first", we might as well give up on introducing new jobs into the game. Sometimes, jobs get grandfathered into things for entirely the wrong reasons. WoW went through similar growing pains when it transitioned from having only one job capable of raid tanking to several, between Vanilla and BC. Sometimes you have to give up turf in order to allow for more diverse job selection. It's a small price to pay for building up more interest for the role.

The physical tank/magical tank identities were always a bit silly because WAR was equally good at both. I'd personally rather see physical/magical only cooldowns shift into the role action side of things, so that you actually have to think about what sort of defensive you want to bring to a given fight instead of always picking Rampart. I'm kind of surprised that Protect didn't take this direction as well, alongside its classic counterpart, Shell.