It'd be unplayable without it. The trouble is that in a normal set, removing counters is generally a minus; in this set, it's a plus. Similarly, in a regular set, throwing -1/-1 counters onto creatures is just bad, but here it allows you to load up creatures who have effects that require removing them.
I do think it could have been a two-drop and still been powerful, but WOTC consistently underrates how good it is to fill out a curve with a one-drop, and unlike some this one is still great to play turn-1.