Earlier quoted context omitted.
> These are the same people who created XHTML, an ivory tower idea nobody was waiting for... who didn't support the most popular layout method at the time, tables, in their new styling language CSS. You certainly could lay out pages using tables in XHTML, but the point of the standard in the first place was to enable semantically sound documents for the sake of interoperability and to facilitate separation of concern…
I honestly don't think either was the purpose. XHTML existed to make parsing easier. The only things you couldn't do in XHTML 1.1 Transitional that you could do in HTML were having unclosed tags and using uppercase in tag names. That's it. Now yeah, the strict version tried to force you into semantically sound documents... but that was completely orthogonal to XHTML vs. HTML. Both XHTML and HTML were available in bot…
That being the only goal would have resulted in a much simpler standard. Extension modules for example is completely orthogonal to that goal. I think that the standards themselves do a good job of describing what motivates them.
> The only things you couldn't do in XHTML 1.1 that you could do in HTML were having unclosed tags and using uppercase in tag names. That's it.
That's true, but ignores the opposite question—what you could do in XHTML that you could not in HTML.