Sorry, but Great Schools is only as good as the data fed into it. They gave an 8/10 rating to the Pacifica California school district. Trust me, it is a sh—hole district.
Now I’m not saying that WI schools have similarly inflated ratings from Great Schools— their ratings might be entirely accurate. I just find fault with your assertion that the site provides an accurate picture of the quality of schools.
Their ratings are fairly reliable around here, so I’ll give it the benefit of the doubt.
On the other hand you may be right, WI schools rated 10 might be crap. Trump may be right about Walker.