The means in such arguments are implied to be unethical or somehow violate the rights of someone. When that's the case, the proposed end result is used to justify the otherwise unethical action.
I've never seen a valid argument of that form and I use this particular phrase as a heuristic for validating arguments. If you have examples of arguments that best take that form, I'd be happy to entertain them.
That's just an a priori assertion that certain means are categorically unjustifiable (by anything, ends or otherwise) because they are inherently unethical, which is irrelevant to the form of the argument.
If you want to make the point that certain means are categorically unacceptable, make that argument (which will very quickly, I suspect, get to a root moral axiom on which no debate is possible, simply agreement or disagreement) rather than raising irrelevancies about the form of the argument.
Fair reply, though I think I've stated my axiom: people have a right to nonexistence. As a corollary: people don't have a right to the existence of others.
I've never seen a valid argument of that form and I use this particular phrase as a heuristic for validating arguments. If you have examples of arguments that best take that form, I'd be happy to entertain them.