Being more strict than the standards already are would be horrible. The Web succeeded thanks to the loose coupling between browsers and documents, allowing us t

Being more strict than the standards already are would be horrible. The Web succeeded thanks to the loose coupling between browsers and documents, allowing us to make browsers which behave the way we want instead of merely porting the original browser from TimBL's NeXT. Writing documents which degrade gracefully isn't hard unless you do it backwards (scripted frills before meaningful content).