If they are never going to raise the cap, it doesn't even matter to hoard things to vendor later. I could see if maybe there was some awesome consumable that was able to be purchased in infinite quantities that cost a decent chunk of gold but honestly once you have all the pets and all the mounts and pretty much all your gear there is nothing to spend money on.
I guess it's easy to say as a paladin that can tank and get instant queues that hoarding items to vendor later is pointless. I'd honestly rather have the bag space to save transmog stuff, rare recipes that I don't want to use yet, profession mats for when the DMF comes back in a month, or even just cool novelty stuff like the fishing hat you get from the fishing dailies.
That said, I've been hesitating doing the Redridge quest line because I'm gold capped with nothing right now to spend it on. I feel better knowing that I'll never have more than 10g and probably never need more than 10g either.
In closing, I wish there were more things to spend gold on. ;-;