Why polynomial time is called "efficient"?

Why in computer science any complexity which is at most polynomial is considered efficient? For any practical application (a), algorithms with complexity $n^{\log n}$ are way faster than algorithms that run in time, say, $n^{80}$, but the first is considered inefficient while the latter is efficient. Where's the logic?! (a) Assume, for instance, the number of atoms in the universe is approximately $10^{80}$.