motorhaven - 9:15 pm on May 24, 2013 (gmt 0)
I block countries based on thousands of web page probes for exploits, forum comment spam attempts, dictionary attacks, malicious crawling, etc. on a daily basis. Google is not one of the reasons.
Blocking certain IP ranges has not impacted real user traffic to my sites in the least, so Google isn't impacted. For instance, my sites had half a dozen real users from China per year (if that many) which might see Adsense, and prior to blocking China thousands of non-user page requests.
There is a legitimate need for blocking which has nothing to do with Google, and it's an admin's decision what works best for their business model and user base. :)