Earlier quoted context omitted.
Well of course if correctness is not a requirement then it's not being paid attention to. That doesn't in any way indicate that it was a good decision not to require it in the first place.
If it had been made as difficult as possible for enthusiasts learning a markup language to get what was essentially text document to actually display anything, it's probably not too much of an exaggeration to say the World Wide Web wouldn't have existed in its current form. It's not as if many of the web's security holes are related to whether a page displays valid HTML markup or not.
I don't think the assumption is justified that enforcing well-formed HTML documents would have been a significant barrier. To me it actually seems easier to have a few simple and strictly enforced rules than having a more or less random assortment of exception to save a handful of key strokes.