I actually see a decent amount of them when I’m out and about in the world, and that’s not only because I’m frequently playing one.
That said - while I love a lot of things about goblins, including the fact that female goblins are literally weaponized adorableness, the short races get kind of hosed when it comes to anything transmog (and the fact that I play a goblin hunter on top of it just sorta makes that part worse). That probably doesn’t help their appeal to other people on the aesthetics side of things.