You're misunderstanding the comment you're replying to. They're not saying you need an exit node to do bad stuff over Tor, they're saying that anybody with the

You're misunderstanding the comment you're replying to. They're not saying you need an exit node to do bad stuff over Tor, they're saying that anybody with the technical ability and knowledge to run a tor exit mode would also choose to use Tor for any bad stuff, and that therefore it seems unlikely anyone who runs a tor exit node would also do bad stuff directly traceable to their own IP.