Well, it is OK to wait reports from others or to start examining some people when certain red flags are raised. It is too expensive to analize with an engine all the games played on the site.
But it would be helpful to know when to suspect cheating. After all, you don't want everybody to report everybody. I also remember that I reported a person and you found out that he was a super-GM who wants to remain anonymous.
It's not the same as a casino. A better choice would be a basketball game. The ball players will try to point out to the refs that their opponent is cheating. A customer in a casino may not care since they're not the ones being cheated.