1. The issue of what is "in your interest" is not so black and white. For instance, one of the reasons Google is still so popular is because it more consistently returns the results we want. On many DDG discussions (or Bing-related discussions when it was still being discussed), this has been raised as a deal-breaking issue for many people. Google's results are often more relevant and useful. This is in part because of Google's vast store of consumer data. Now, you may argue that their results are better for other reasons, but the fact is that using their consumer data is an integral part of their ranking algorithm, and people like their ranking algorithm.
2. On a more cynical note, it seems that governments and corporations are aligned in their interest to collect as much data about citizens as possible. I doubt that the U.S. government will mandate a reduction in storage of consumer data, when they themselves benefit regularly from that data thanks to widespread use of NSLs and other legal and extralegal demands.