Why don't self-closing script elements work?

Question

What is the reason browsers do not correctly recognize:

Answer 1

In case anyone's curious, the ultimate reason is that HTML was originally a dialect of SGML, which is XML's weird older brother. In SGML-land, elements can be specified in the DTD as either self-closing (e.g. BR, HR, INPUT), implicitly closeable (e.g. P, LI, TD), or explicitly closeable (e.g. TABLE, DIV, SCRIPT). XML, of course, has no concept of this.

The tag-soup parsers used by modern browsers evolved out of this legacy, although their parsing model isn't pure SGML anymore. And of course, your carefully-crafted XHTML is being treated as badly-written SGML-inspired tag-soup unless you send it with an XML mime type. This is also why...

hello

...gets interpreted by the browser as:

hello

...which is the recipe for a lovely obscure bug that can throw you into fits as you try to code against the DOM.