Strictness works well when you have a small number of active producers and consistent, constantly renewed content.
The web is the opposite - a huge number of producers and widely varying content, some of which is 1-2 decades old and will never be updated.
You can design and build a great, strict HTML parser - it just won't work well for a significant portion of the www.
And if you make one that is popular enough, you can change the direction of evolution of the web! (See mobile safari and flash)
Strictness works well when you have a small number of active producers and consistent, constantly renewed content.
The web is the opposite - a huge number of producers and widely varying content, some of which is 1-2 decades old and will never be updated.
You can design and build a great, strict HTML parser - it just won't work well for a significant portion of the www.
And if you make one that is popular enough, you can change the direction of evolution of the web! (See mobile safari and flash)