Part of the problem is that the spam team IMO is largely comprised of people that have never owned businesses. They have no understanding of how devastating their little 1% changes are to many honest businesses. Saying that we shouldn't rely on google is like saying people before us shouldn't have relied on Bell to make the phones work or to deliver the yellow pages.
We are watching the unmitigated biggest spammer in our segment dominate on every term. All with blog back links stuffed at the bottom of a paragraph or in sidebars, advertorials, directory and paid links from the directories. There are countless dead pages ranking in the top 3. Test sites, sites with banners that read "under development" or product searches to amazon pages that say its not longer carried ranking first.
The spike today in ad spend is incredible but it is also terrible non converting traffic.
I cannot believe for a second that the display layout changes are designed to increase the quality of results. Placing barely relevant ads above everything else isn't increasing the user experience its increasing googles revenue. Bottom line it's that simple.