I'd even say take away their posting rights, or at least limit their bandwidth severely so they can only make one post/vote per day or so. We have seen some discredited accounts continue to spam randomly and incessantly, often with hateful messages. They give up after a while, but it's an unnecessary inconvenience. No new user posting an introduceyourself message wants to be greeted by a message, even if hidden, saying "Steemit is a scam, X whale is evil etc. etc.". (Yes, I have seen new users respond to these.)

As for Reputation, the current system simply doesn't work. Anyone who makes a lot of posts and gets voted by the same people over and over again stands to gain a high Rep. Conversely, any one could single out a new account, get some help from their friends and repeatedly flag it to oblivion; even with relatively low Rep or SP. As smooth points out, I'm not sure if there can be an effective Rep system, but I'm sure we can do better than this.

Off-topic - I'd love to see you comment more! Not just about Steemit stuff, but in general. Your comments about Vaccination yesterday were a tour de force of rationality - much needed on Steemit. :)