And large bitmaps are rather bandwidth inefficient, and inaccessible to boot.
I don't mind markup. I mind tech that doesn't include fallbacks, and I mind people using Turing-complete languages for things that can easily be done using a less powerful language. (Turing-complete languages tend to get abused by people to the point that people want them to be executed quickly and with little memory use (which means that the language implementation gets complex, and hence buggy {simple laws of probability}), and almost any vulnerability can generally be exploited by a suitable script in a TC language, and TC-languages can be used to do unexpected things.)
HTML is decent. HTML+CSS is worse than HTML (for the same reason that COMEFROM is worse than GOTO). Markup is better than HTML in many ways, or rather most formal specifications of Markup-like languages are better than HTML. (Unfortunately, most variants of Markup aren't specified beyond "do what I do")
I've been tempted for a while to write a Markup browser. (Mop? Markup-Over-tcP? )