The challenge in using Counterflux is the mana cost.
If you have it in your opening hand its already a dead card. Player have to wait for 3 turns / 3 lands to utilize it. Which a lot of things already happened, by the time it is useless.

Then if you have wasteland as your 3rd land cant use it because of the mana color that is required for it.

Then the next challenge is what card to replace it the deck is already tight without it.