Were you not expecting to have to convince anyone? If that really is so, then again I have to ask, do you imagine this sort of thing normal? Are you in the habit of letting harangue stand in for conversation in ordinary life also, or is this a special occasion?
Neither side persuades the other, and the thread becomes more about rhetorical sparring than the original topic.
Now we have an illustration of precisely what that means, more or less entirely in spite of those irritated into furnishing it.
Oh, I understand why rhetoric gets a bad name. No fool ever likes being made to look foolish. That's worth doing, in public, as often as possible, with the kind of person it takes to look utilitarianism full in the face, 'repugnant conclusion' and all, and still embrace it.
Easy, your utility function is an indicator on WWPTD (What Would a Priest of Tezcatlipoca Do)?
+1000 when your actions are in accordance with a priest of Tezcatlipoca, and -1000 when they are not.
Like string theory, you can make utilitarianism fit anything. So on its own, it is neither good nor evil.
It entirely depends on which utility function.
I appreciate your honesty.