> Lastly, the insinuation of the article is that "unbiased" search results are clearly preferable.

the insinuation is that you should know if they are biased or that you should be able to get unbiased result if you so wish.

It also raises suspicions on how much google tracks each user.

From this point of view what would be interesting would be a local study, to see in 100 people all in the same neighbourhood with different browsing habits have different results. this would eliminate the "non-tracking" part of the personalization.