Okay, I'll bite. Why not use XHTML 1.1 if you want to add your own validating DTD? The reason we went HTML5 is because the validator mattered only until it stop

Okay, I'll bite. Why not use XHTML 1.1 if you want to add your own validating DTD? The reason we went HTML5 is because the validator mattered only until it stopped being important. People realized that, for end-user use cases, they want to see website content in their browsers, not "this page is not valid XML" error messages. And weren't web components pushed aside to HTML 5.1 since it's not finalized and we wanted to call work on "HTML 5" completed? And I fail to see how XHTML, being simple markup, would do anything to assist with an AJAX call. It's HTML5 that you have to thank for the async and defer attributes for scripts, that reduced some of the need to use anonymous functions to do the same thing. Effectively, HTML5 has been as much about speeding up browsers as speeding up web development--and in the process, the user's happy too because they have no idea what's happening inside their browser, but things stay compatible. After all, no one was updating old sites to be XHTML-compliant and yes, there were too many non-validating sites. So we just stopped worrying about validation as much, as far as XML goes.