Blue
Ravenous Bugblatter Beast of Traal
Perhaps. I still think that the initial Counterspell caster is at a significant disadvantage because they have no ability to make an informed decision regarding the expense of a useful resource (that Counterspell could be a Fireball) but anyone else who wants to Counterspell them, including the initial caster, all but knows that they're casting Counterspell. It seems like a cheap way to attrit player resources and makes the whole thing a wheel of fortune guessing game.
But that's true regardless if it's PCs or NPCs attempting to counterspell the counterspell.