That's his point though. Say he reports it, what is it really doing? It's not doing anything to stop the system from running amok. Boosters will just find more players to pay as the ones that accept money are suspended and ultimately replaced. Programs will simply bring in more players and the system will continue replicating itself. So what is Tressel going to accomplish by turning those players in?
I'm not saying he shouldn't turn them in, but Whitlock's point is that the problem is NOT the coaches turning players in or not, but rather that it's well beyond the scope of what a coach can control. The rule itself is not even realistic. It might make fans feel better when another program is caught cheating, but realistically it doesn't change anything. It's still going to happen both at the place that cheated and their own favorite institution that hasn't been caught.
As far as Tressel, it's still a fair argument that he wasn't trying to cover anything up. It's not an unfair stance that he thought the information would surface at some point, so perhaps he'd abide by the requested confidentiality and let the legal system play out. After all, whether you believe him or not, the emails do show that he was asked for an expectation of privacy in the matter, and it's not hard to see how that would be a predicament for some people that respect the legal system too. I believe you've worked in the legal system, as you've stated in the past if I'm not mistaken, so couldn't you see how it might be a reasonable concern he had? Whether that was his true intention or not, we'll probably never know. But that wasn't a decision you or I was faced with.