I don't see any current benefit to having each mount be locked to what Grand Company you are currently in, when the PVP system is no longer locked down as it was back in the day with GCs. It would be cool to use each GC Warsteed without having to switch grand companies each time.
EDIT:
To clarify, this is NOT to remove the GC achievement requirement or anything with how to get them, we need that for grind incentive.
Example: I have the Flame Warsteed mount. I am currently Adder GC working towards the Adder Warsteed, but I cannot mount the Flame Warsteed (or Mael) in open world. We can ONLY use these mounts when ON that specific grand company. Hope that helps.
Also yes they're ugly and dumb, but I want to be able to use them ALL in open world.