I am confused as to the point you are trying to make - you seem to be saying because IP geolocation doesn't work for you, it doesn't work.
No, I'm saying sometimes it is more accurate and sometimes it is less accurate. Which is substantially what you're saying, but you just want to sound superior. You don't really know whether this case is more or less accurate than anyone else's results.
In my experience of deploying consumer broadband networks for a national ISP (think millions of consumers)
Hail the ISP genius.