Why is there no standardized wiki markup language?

Question

For as many wiki tools as I have used, each time I must learn yet another markup language. Why doesn't wiki markup get standardized like HTML, XSLT, SVG, and other web languages?

Answer 1

1. No standard libraries--unlike, say, RegEx, which is baked into various platforms, which tends to stabilize the de facto standards. There are standard implementations, such as MediaWiki, but not everyone wants to use MediaWiki and there's little incentive to copy its rather robust markup language.
2. Little need to exchange data between wiki platforms.
3. Few common users interact with multiple wikis, so they learn the ones they are exposed to.
4. Wiki markup is essentially a hack to overcome poor rich text browser control implementations, but rich text controls are getting better. (Templating via wiki markup is, of course, a whole other topic.)
5. Wikis are often domain-specific, so the available formatting options, suitable characters for markup, etc. differs between implementations.
6. There are existing competing "standards" such as BBcode, which further confuse the whole tag-vs-character-markup decisions.
7. If an entity such as the W3C came up with a standard, it would take 3 years to develop, an extra associate's degree to use, and no one would rewrite their wikis to support it.