A small number of SE sites might have them turned off —I think we've had the opportunity to tune how much we use audits— but they're generally a good thing for the community.
If you are banned from review, I'm sure you probably have a very different view on audits. I personally hate failing single audits. However, review bans aren't handed out for single fails; you have to fail many audits. It's not a problem with the system, it's a problem with your reviewing.
The ban gives people an opportunity to step back and look at what they've done to earn the ban. In many cases that just means learning what is and isn't acceptable on the site.