The main thing I wonder is why are the trolls who repeatedly hijack threads not banned? Most of it seems to come from the same 1 or 2 guys. Why not ban them and every IP address they've ever thought about using?
If you're on a cell phone, clear cookies, cycle airplane mode. Takes 10 seconds. Suddenly you're unbanned. The cell networks have millions of IP addresses, you would have to ban every single one.
Anybody on their computer on DSL or fiber can just reset their router. Takes longer, but still possible as well to get a new IP.