If the outcome is negative, all a utilitarian can do is change is game plan for next time, sort of a sophisticated "trial and error" philosophy.
Isn't that the essence of conservatism, if I may be so bold? That the institutions and social structures that now exist are the result of millennia of trial-and-error, and that they represent the "tried and true" methods of organizing society? And that, as a result, we ought to be loathe to simply discard them on a whim?
I'm not a conservative. I'm a Christian constitutionalist, just as our founders were. There is nothing left to conserve. Right and wrong never change, so I do not believe in pragmatism - it's machiavellian, marxist, and morally relative to the ruling power. We should not do what works, but we should do what is right. Sometimes the right thing is the hardest thing.