Just so you know when you have a comment with "why the hell can't…" it doesn't exactly come across as friendly and it puts whoever you directed it to on the defensive. It will generally lead to something equally unfriendly in reply. My apologies if I came across harsh in my reply, but that's where it came from.

I do understand your point, but you have to remember what validation is. It's not some kind of absolute moral imperative we all have to follow 100% of the time or we become bad coders. I do think people should take the time to write valid code for the reasons I pointed out in the post. I know it helped me learn to code better.

But there are certainly times where it's perfectly fine to write code that's not valid. Vendor prefixes are an obvious case. It's not like they're going to break anything or cause problems for any browser. You could write perfectly valid code and add a few extras for those browsers capable and you're page is not longer 100% valid.

It doesn’t need to validate if it works…

Where exactly did I say that? I don't think I've said anything to suggest that's my attitude. I'm saying I think people should take the time to validate, but I don't think they need to stress if they have reasons to allow validation errors to remain their code.

Why the hell can’t the internet be flawless, valid and nice?

It would be nice, but sadly we end up relying too much on code we don't have any control over.

A few years ago I wanted to use some code from Google. I forget exactly what it was, but I'm thinking it was their custom search. It was when I first built this site and at that time (before all the plugins and social buttons) every page here was 100% valid. Google's code wasn't. I emailed them to ask if I could rewrite it to make it valid and they wouldn't allow me to use it if I did. So it never went on the site.

Years later I realize it's a trade off. How important is what you're trying to achieve as compared to keeping 100% valid code? Is it worth having every line of code validate if it means providing a lesser experience for visitors to your site?