Well, I can't really argue comedic tastes because those are too subjective. But I will say these kinds of jokes are made with the presumption that none of us actually approve of slaughtering millions of innocents over something as trivial is a movie, and with the further presumption that it would never actually happen.
If the Transformers Genocide ever actually happens, I guess that'll be me retroactively looking like a bit of a dick. But I'm willing to roll those dice, I guess.