There certainly is a lot of moral prescription going on. This is mostly indirect, implicit in the kind of questions that get asked rather than directly asserted. "Expected utility" is the right thing to optimise for, almost by definition. But there is more than that at play. In particular, there tends to be an assumption that other people's utility functions will, and in fact 'should' contribute to mine in a simple, sometimes specific, way. I don't particularly respect that presumption.

Edit: Fixed the typo that cousin_it tactfully corrected in his quote.