Who Cares?
Just because you can only think of an exponential solution to a problem doesn’t mean that there isn’t a polynomial time solution (remember the mutilated checkerboard?).
If a problem is in P it is also in NP by definition (similarly, if it’s O(n2) it’s also O(n3), etc.)
Reduction of a known NP-complete problem guarantees that there is no polytime solution unless P = NP.