What's the point of valid CSS/HTML?

Question

If I\'ve tested my pages in most major browsers, why would I need to maintain a validated code? I want to use box-shadows and corner radius if they\'re supported in WebKit b

Answer 1

"Valid" code isn't so much important as "semantic" code. If there are font tags all over the place and list tags that don't close, it'll be both difficult to maintain and hard to parse with strict and proper xml parsing engines.