Friggin dislike this argument. I've heard it so many times, like "All other artifacts are shit because Doomhammer etc.".
Doomhammer is a piece of fucking metal, infused with power of some nameless fire elemental - a bit. Nothing spectacular at all. Compare that to a fist weapon infused with power of a Titan, wielded by the most powerful Watcher on Azeroth. To a staff wielded by Sargeras himself. Hell, there's even a reforged Frostmourne in the bunch.
It's not nameless crap, it's new stuff they invented because, well, the game didn't end on WC III. The lore keeps moving forward, and weapons are created along with it. And it makes way more sense to give us a new, intriguing weapon to discover the potential for, than to get a mace wielded by a few orcs because of its "hits in the head" ability.