I know it's hardly a pressing issue for most folks but I still wonder about it. According to Wowhead there are 69 fist weapons in the game. Thottbot lists the same ones. Meanwhile, there are over 300 one handed maces, over 300 daggers and over 300 one handed swords that Wowhead brings up on a casual search. One handed axes are the next most unloved (if that makes sense) at 167. That's still 100 more axes than fists.
The real issue isn't fists for endgame, or even fists for the old level 60 endgame. You can get nice green fist weapons starting at level 57 and there are nice fist weapons in the instances. But aside from gems like the Claw of Celebras or the Vilerend Silcer, which are still relatively late in the game at the mid 40's, what pickings are there for the lower levels? Looking at the options for a decent green fist weapon when leveling up, you'll basically see that there aren't many. You can get a crafted fist at level 27, then if you're horde you can get a quest fist at around level 52, and there's a green fist or two dropping in BRD and Dire Maul.
Now, I like fists and I'm glad that The Burning Crusade introduced more of them. But can anyone think of why they're so rare? Is it that they tend to be too fast for anyone but a fury warrior, as one person commented about the Vilerend? There are some nice fist weapons waiting in the level 70 instances and raids, why don't we see more of them before that? I'd personally like to see more of them, but I may well be in the minority here. I've tried to get the best fist weapons I could on my shaman and on my warriors, going so far as to take the Mag'har Fury Brand over the Honed Voidaxe, so I must be really into punching things. Is there a particular spec of your favorite class that benefits from fists, or are they always the poor option?