USAID was a highly effective and efficient operation. Musk dismembered it, leading to untold misery, death, and the spread of infectious diseases. I think this is reason enough to hate Musk.
Also, keep in mind that what Musk did was a violation of the separation of powers in the Constitution, so he simultaneously killed a program which saved lives while he also started the U.S. on the road to authoritarianism.
The race to the highest body count looks like Elon in first, RFK jr. second, and Stephen Miller a distant third but looking like he'll finish strong once the camps are fully operating.
I would argue without Musk and his Twitter/richest man of the world power, Trump would have never been elected in the first place, which would have prevented this and a lot of other bad things. Still, I don't hate him. (Hate is not a condition I think is healthy or constructive or something I should explain myself not feeling it)