[crazygringo]

I can't tell if you're joking or not.

Utilitarianism has always been more about government policy, so yes it's largely inappropriate as the foundation for a system of personal ethics, at least in its basic forms.

But I'm unaware of any university class that has ever attempted to "build a real system of ethics".

That's not what moral philosophy classes do. The whole point is every moral system encounters major showstopper flaws, and how to reconcile those is one of the great unsolved problems of humanity.