Basically the ends don't justify the means (Among Humans). We are nowhere near smart enough to think those kinds of decisions (or any decisions really) through past all their consequences (and neither is Elon Musk).

It is possible that Musk is right and (in this specific case) it really is a net benefit to mankind to not take one minute to phrase something in a way that it is less hurtful, but in the history of mankind I would expect that the vast majority of people who believed this were actually just assholes trying to justify their behavior. And besides, how many hurt feelings are 55 seconds of Elon Musks time really worth from a utilitarian standpoint? I don't know, but I doubt Musk has done any calculations on it.