That is ridiculous. Sure it isn't the best resource available and on some things makes some out of date or wrong recommendations. I have gotten refreshed on basics plenty of times though from a wc3schools links. Does that make me less of a developer?
You are also implying that developers using windows are all second rate.
> I have gotten refreshed on basics plenty of times though from a wc3schools links
When even the basics are wrong you're not getting refreshed much. Especially when adding three letters ('mdn') to the query at the end gives you a much better resource by all metrics.
What I'm implying is that a lot of Windows developers don't have a choice. It's the standard issue computer they're given. Maybe they work for a gigantic company with a fossilized IT department. Maybe they work for the government. Either way those kinds of organizations are not running Linux or OS X or Chrome OS. There is a very strong bias towards Windows because of that.
If you subtract that quotient from the general pool of "Windows developers" it becomes much more of a fair comparison.
Yes, there's useful things on w3schools, but like picking through a trash heap full of rusted bicycles and used syringes, it's a dangerous expedition. You might pick up some awful bad habits along the way.
You are also implying that developers using windows are all second rate.