If people would like to discuss this, they can at least discuss it for what it is - an attack on the program. Treat it as such. Don't hide behind "he just wants to talk".
There are, no doubt, many people who discuss Google's diversity programs every day on a good-faith basis. They don't need a manifesto in order to do so.
What's the problem of wanting some light shed on a program because someone openly believes it should be shut down? They're not doing an executive decision to shut it down without allowing for discussion, which is exactly what Google management is doing. He posted an opinion, partially based on facts and partially based on conjecture to bring attention to it.
In short: there's nothing wrong with wanting a program to be shut down and using that as motivation to put it in the spotlight. I don't see how motivations should get in the way of discussion and examination of existing systems; a system that is beneficial to it's environment should be able to stand on its own merits.
ugh, my "in short" is as long as its preceding paragraph :(
I hope you'll forgive me for saying it but that is my definition of the "burying your head in the sand" expression.
edit: furthermore, what if he's in fact saying that he wants them to be cut down? Why isn't that a reasonable motive to want something to be more closely examined?