"Why not?" Because invisibly tallying a view count is completely different than displaying a visible advertisement.

Right, it's the same as asking why you don't expect an adblocker to block you from ordering pizza online - i.e. a stupid question. You expect adblockers to block ads and not block things that aren't ads. A lot of them block pointless analytics stuff but when this is actually an important part of site behaviour, it shouldn't be blocked.

How do you know what Google is doing with the data?

If it's using the same profiling to determine if you're unique, and sending it to the same datacenter that builds the ad profiles, how is the adblocker to know that the endpoint is really only invisibly tallying a view count?