NP-hard doesn't automatically mean "too hard", just like "solvable in polynomial time" doesn't automatically mean "practical".
I know you didn't claim that, it's just that I've seen one-to-many arguments that consist of "NP-hard, therefore not doable"
If a problem scales as 1.1**n and n is expected to be 100 at most, then it's easily doable (barring huge constant factors), a n**7 algorithm is actually more computationally intensive up to a n of about 350.
I don't know how large the problem-space tends to be for scheduling-problems though.