For most other rules, I understand and agree with the idea of needing to provide a temporary ban; a lot of rules aren't even read by players and are assumed to be rules (e.g. camping in the sky during sky wars). But using hacks is such a premeditated and determined effort to cheat, I really don't think a temporary ban is acceptable. Just ban them permanently and be done with it.
Before starting, I want to say I totally understand the standpoint of this post. I play a good bit, and encounter hackers a lot, and nothing sucks more than knowing that even if you do manage to record them, report them, and successfully get them banned, they'll just be back next month. I mean it's frustrating, and believe me I feel for you.
However as many above have stated, the benefit we'd get from making hacking instantly bannable would be relatively neglectable. You would still see the the omega hackers to have the hundreds of accounts flying around, kill auraing in your games. This rule change wouldn't affect them in the slightest. Besides that, people who are accidently banned and don't know how to appeal (so likely kids), they would get banned with no way of ever coming back. (which again doesn't really help the hacker situation) Do I have a solution to offer? No not really. However, I really don't think this idea would end up doing us much good.
If anything, I'd argue the punishment for breaking rules like Teaming in solo games is far too lenient. Unlike sky basing or other rules you might 'accidently' break, this one entails way more personal responsibility. It literally says teaming in solo games is a bannable offense at the start of every game.
I might start a thread discussing that.