Again, I understand what you're saying, but it just doesn't make any sense to me.
#1 - A beginner doesn't know what IS correct, and what ISN'T
#2 - There are a wealth of other sites out there that DON'T have the glaring errors that w3schools do.
Seems a bit of a no-brainer to avoid that site altogether. Whatever works for you, I suppose, but trying to convince me that it's worthwhile to send a single person to that site, regardless of their skill level, is an argument you're never going to win.