Google knows this and they have an incentive to move "commercial" sites towards AdWords and move "informational" sites higher in the organic results. The benefit is engineers can claim they are providing a better end user search experience while AdWords can make even more money.
The bigger problem is that the top 10 on a search string can be very arbitrary. What should be the top ten for the search term "shoes"? Wikipedia? Zappos? Local shoe stores? A blog about shoes? Are the top 10 the top 10 because they should be there or simply because Google put them there?
Nextag is an example of a company built on a platform (Google organic search results) that is somewhat hostile to Nextag's business. It's similar to the whole Twitter client app situation. Nextag needs Google, but Google doesn't need Nextag. It's an unequal partnership of sorts and Google doesn't care of Nextag exists.
It's too bad, but that is the nature of Google's platform.