The reason that such arguments do not work is that you can specify exactly what it is you want to do, and the programmers did specify exactly that.

Which is part of my point. Because you can specify exactly what you want--and because you can't for the kinds of utility functions that are usually discussed on LW--describing it as having a utility function is technically true, but is misleading because the things you say about those other utility functions won't carry over to it. Yeah, just because the programmer didn't explicitly code a utility function doesn't mean it doesn't have one--but it often does mean that it doesn't have one to which your other conclusions about utility functions apply.