Could someone who is Web savvy explain what is going on between Google and my Web page tracking service?

I use the StatCounter Web service to monitor the traffic on my Web site. It is a free service with unobtrusive advertising and has been fairly reliable. I noticed though that the listing of hits by keyword showed that most were unavailable. I just got a notice from them that is summarized here It may be hard to read the setup information on the blog page. Basically they asked me to add my a Web site to my Google account and to add StatCounter as a restricted user for the site.

My first question is why Google would want to suppress keyword information for people’s Web sites. That seems pretty nasty of them. My second question is how StatCounter is able to recover any of that information.

I followed the instructions that they gave and can see the statistics that they refer to.