The thing to remember about CISM is that it's firstly designed to get controllers (and other staff) 'settled down' and back to work as quickly as possible. Whilst the concepts are good, like anything else, in the wrong hands it may not achieve much.
Whilst we will each have a different opinion and experience, I find CISM to be a case of giving what should be common sense and professionalism a fancy name. As ATC Watcher points out, a CISM scheme will have trained 'peers' - sadly, my experience is that those selected to be peers are sometimes the last people who should take on the role. In the worst case after going on a course one such suddenly became an expert in all things 'Human Performance' and claimed an unassailable expertise.