> On the actual spec/implementation: yes, it's a complete disaster. Especially the way it is kind of mapped on to HTML, so you get weird things like writing "1. blah; \ 1. blah" makes a numbered list with a 1 and a 2.

There is a trade off here though. When people sit down to write something that doesn't have weird edge cases they're not likely to end up with a lightweight markup like Markdown.

So simultaneously the spec may be a complete disaster and a contributing factor Markdown's success. Much like how the human brain is very bad at adding numbers together and has so far effortlessly out-competed alternative species that had brains that were great at numbers but not vision processing (being great at adding numbers is so useless for an animal I assume the skill never evolved, but imagine there was a creature somewhere with amazing additive powers for the sake of argument).

Having an unambiguous spec could theoretically be a disadvantage to adoption outside of a very carefully designed markup.