I'm not sure if making a living without having to pony up hardly any initial expense nor have any legal exposure makes us idiots. The vast majority of AdSense publishers are getting a whole lot more than they have to give.
That won't last forever. Once MSN and Yahoo! catch up there will no doubt be more info available. Especially if the others allow it. It will probably encourage Google to keep disallowing income disclosure for publishers, but hopefully they will divulge their take.