For the most part, it's not Dex's fault. A properly maintained coolant system will not have any problems with Dexcool. The problem is when air enters the system or slightly failing gaskets (internal, so you'd never know). Then Dexcool reacts adversely to the contaminants.

Yes, there's a Dex suit out there. But, if Dex was the problem, why aren't all of GM's cars involved? Its only the ones with gasket issues like ours...