I don't know how long you think it took ( https://github.com/paulirish/w3fools ) but it took a couple of hours of time from a few people over about a week.
I'm not sure the last time you built a website to scale and to the breadth of information that's found on w3schools (valid or not), but it takes a hell of a lot longer than a week.
And just because the creators didn't build a clone of w3schools, doesn't mean they aren't contributing useful information back to the various communities affected by the nonsense published at w3schools. Every single one of them are writing blog posts and submitting to open source projects, hosting podcasts, helping on IRC channels and forums, and building helpful websites to learn exactly the same stuff found on w3schools, except with valid information.
The creators of w3fools have no issue with the other resources that are available that they suggested as alternatives. For more specific beginner data, there are numerous walkthroughs and helpful answers littered across the internet with the correct information in them. Creating yet another site that puts together tutorials isn't what is needed. They want the beginners to be able to have a fair chance at good knowledge. Creating a site to slowly gain google juice over the next two years does nothing to help people today. Until w3schools stops showing up first for every "___ Tutorial" search in existence, the job of making it a notoriously questionable resource will do way more good than building a shadow site would do. If at least you are somewhat aware that you should fact check the things that you learn there.
I find it a little bit troublesome that the group that follows 'hacker' news is so willingly supportive of blatant technical misinformation. You can nitpick about some of the things that are brought up, but as a whole, it's ridiculous that the number one resource for technical information is so wildly out of touch with reality. You can question the method that this was brought up, but you should still have the desire to see good information in the wild.
And finally, yes, there are other out of date websites that have tutorials on them, but they don't show up first in google, and they don't sell certifications based on their misinformation to unknowing people who don't realize that the certifications mean absolutely nothing (and are potentially detrimental). Get mad at whoever you want, but objectively speaking, the site is a disservice to the community, regardless of it's ease. Getting bad information is _always_ easy.