Also, utilitarianism never claims something is "wrong" or "right" -- that's a spandrel from deontology. Utilitarianism is a claim about the ranking of actions: some actions are better than others.

We're not fighting to make the claim "doing X" is the ultimate and nothing is better -- with the world of nearly-infinite complexity and unbridgeable uncertainty, the best we can do is point out what seems, based on good evidence, as things to do that seem better than others.