I'm sort of stunned that people would think that it is. I certainly never got that impression and I've used the site many times.

It seems to me that those with the most to learn from such a resource would also be those least likely to know what the W3C is.

If you stopped me on the street and asked me yesterday what W3schools was, I could have told you exactly. not so sure I'd know what W3C is without context. I guess this places me on the low end of the spectrum. :-)