Pointed Discussion

If you need cards and know that getting them will be of more use to you than your opponent, go for it. Or just Voltaic Key.

AWOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO

Voltaic Key untaps artifacts, so it won't do anything for you when you presumably want to tap Howling Mine. Icy Manipulator will do it, but that card has better things to do. Clock of Omens can do it by tapping itself and Howling Mine, then untapping itself or a third artifact you may want to use again, like any number of numerous mana rocks. That's your best option. But if you really need more, Blinkmoth Well actually has a use with Howling Mine, and Lodestone Myr gets a tremendous +1/+1 by tapping the mine! But seriously, Clock of Omens, not Voltaic Key.

you dont want to tap it if you cast it (cuz you obviously have a use for it), and you won't put an artifact tapper into your deck just for this. so this arguement is fruitless, unlike utopia tree.