Valve developer John Mcdonald has been on a social media answering spree of late. He has been answering community questions and trying o establish a dialogue. In a recent tweet, he mentions problems in permanently banning players from the game. This is why Valve chooses not to ban hackers but instead work on the VACnet to help remove hackers from the game altogether.
I think you've described the problem there exactly. When someone cheats, we *do* permanently ban their account. But banning them is hard. Banning these doesn't work:
IP address, hardware, payment information, email, …
The internet makes this super tricky. https://t.co/z3psOatU3i
— John McDonald (@basisspace) May 12, 2018