Guys who are going to throw games and cheat the system to avoid DQ are going to do that anyway. In this guy's case, I'm guessing he wouldn't have played singles leagues at all if he knew those matches would jeopardize his 3.5 adult rating since it's clear he was willing to go to great lengths to preserve that rating.
You make it sound so simple, but the crux of the matter is that you can't control cheaters no matter what you do, and most of the penalties that are put in place end up catching people who are playing honestly rather than those that are willfully manipulating the system. The manipulators are too smart to get caught.
I really have no problem with Sections wanting to do their own thing.