Just to balance this off, there are thousands of advertisers who do not express that they are quite happy with google (but they are)and the truth they have been offered. I would certainly like more information about what google does and how it all works, because I'm a curious guy.
But I believe that given the issues google has to face regarding how any information it provides can be used to game the system, and basic proprietary info, I'm really content with the routine 'how to'.
When I look around and take the initative to find out things about google, I start to find all kinds of information that has been presented by google staff (I just listened to Kim Malone on webmasterradio who explained a bit about the appeals process for adsense).
There's lots of stuff out there, enough to convince me that google gives a reasonable amount of explanation. But it's OUR responsibility to look for it. Yeah, google could be better at it, but if you want to find out more, you can research some of it.
Finally, I think most of us understand (even when we get frustrated)that a) it's not google's job to tell us how to run our businesses successful and b) that no matter what google does or says, a lot of people (in fact the same people) will complain, accuse, even libel.
Given it's a part no win situation for google, I'm happy with the flow of information. I'd like more, but I don't expect more.