It's always been possible for a site owner to track certain things via access logs, I think Google should still allow for those basic metrics to be tracked via Google Analytics.
While it's still possible to track site usage via logs, I don't think Google should give end users a way to bypass the wishes of a site owner. If someone is using my site, I believe I have the right to have access to certain usage information. (Insert bit about doing it ethically)
In the past, Google Analytics has been good enough, and I've not felt the need to analyze my server logs. Now I question how popular this plug-in will become, and how it might skew even the most basic and fundamental usage stats.
By providing an all-or-nothing plug-in, Google is hurting those using Google Analytics more than it's helping to ensure people's privacy.