Oz, I wish him success as well, but I liken it to having a crazy nutjob advance your cause. If this guy is the one they see, it tinges any other efforts in the eyes of the people that need to be convinced. Basically, even if your goal is preventing child abuse, you probably want to get a different spokesman than Charlie Sheen. You don't want the people you need to hear the message to have to wade through the crazy to get to your message because they won't. You have probably 30 seconds to get their interest to move forward, not 30 hours for them to read that doc that starts out with "wade through my crazy first". Instant dismissal and then association of the crazy with the next person to stand up and present your case, even if the next person is James Earle Jones because they are still thinking of Charlie Sheen.
Having balls of cast iron and being a nut in no way mean he should be supported. The road to hell is paved with good intentions.
[Edited to add] Aussie, family-wise, I am in the same boat you are, so I have a ton of sympathy and follow your story closely as I am a few years behind you in terms of what to expect. I agree with your sentiments and wishes, just .....not that this guy should be the champion for the cause. When I want someone to stand up in court to represent me, I don't care if his heart is in the right place, Gary Busey isn't my first choice.