The notion that he was killed, or intentionally allowed to kill himself, or similar, isn’t that the government just hated him so much for his crimes that they wanted him dead. The suspicion goes that he had evidence on some or all of his clients, that he might’ve revealed for one reason or another, and was presumably killed to protect them.

They’re not feeling sorry for Epstein, they’re mad because they got told “there’s a bunch of child abusers out there, to include some percentage of the rich, famous, and politicians running the country, and you’re never going to know who they are, nor will they face any penalty”, and they want to see something done about it.

Further, it can tie into existing political polarization. If you know some percentage of especially the people in politics are abusers, but you don’t know which ones, the natural tendency is going to be to assume that it’s mostly the side you don’t like (because of course, one already trusts those people less than one’s own side).

This gives one an excuse to hate the other side even more (this isn’t to say that this issue is evenly distributed and doesn’t actually affect one side more than the other, but that the everyday supporters on both sides both think, rightly or wrongly, that the list is predominantly the politicians and celebrities that they don’t like, and view it as a potential chance to see those people removed from power and punished for a deserved reason).