I think they were making a (poor) analogy, not literally accusing Musk of committing genocide.

Well, i can't think of a better analogy to say that you can't offset doing bad things by doing good things. The karma system some games use (e.g. Fallout 3 where you can nuke an entire city that puts your karma in negatives and then give fresh water to beggars to reset your karma) was what i was reminded of.