It's all about where you put the horizon in your short-term thinking. It's sort of like refusing to have your army defend against an invasion because some of your soldiers may die, when you're pretty sure the invaders are going to kill more people than that anyway if not stopped.

If Tesla's management really believes they are changing the world and having a non-negligible impact, then they might easily justify to themselves that while they aren't the most benevolent of employers, they make up for it with what they do. The problem is that a) people may not even agree their goal is beneficial, or b) accepting the prior as true may not agree the degree to which their actions are beneficial in the end, or c) accepting both the prior as true may not care because those actions may disproportionately affect the person in question.

In any case, I don't think it's as simple as you make it out to be.