1) Since when has Google been "clobbered in the pocketbook?"
2) The most "relevant natural search results" will exclude boilerplate affiliate pages and other SERP clutter, so forget any conspiracy scenarios involving "the bright boys in the accounting room." All Google has to do is live up to its corporate mission statement--"to organize the world's information and make it universally accessible and useful"--and ad sales will fall into place.
3) The "profit split" between Google and publishers isn't a "super secret." See Google's most recent financial statement.
4) As usual, too many WW members are making universal assumptions based on their own personal experience. Fact is, not all AdSense publishers are seeing a drop in CTR, CPM, or total earnings. Some are continuing to do quite well, and some have seen increases.
As for whether the reduction in direct-to-merchant affiliate ads is hurting some publishers, that may be a possibility in some sectors--but definitely not in all.
Bottom line: As usual, some publishers are up, some are down, some aren't seeing any change, and some of the ones who are hurting need to vent their frustration by putting the blame on Google instead of accepting the realities of an auction-based marketplace.