Comment by da_chicken

Eh, the things Markdown was made to compete with were also text. Including, you know, plain text. Sure, there were people out there doing README.RTF or README.DOC that annoyed us all -- nevermind those README.PDF monsters -- but just as frequently it was README.TXT or READ.ME (or README.DOC was in plain text). And GameFAQs and newsgroups got pretty far with plain text and ASCII graphics.

The problem is that people want to use a web browser to display their documents, they want rich documents, and web browsers are awful at displaying text they don't understand the structure for. And <code> tags look consistently awful when read back, which is why we so strongly prefer syntax highlighting when we read XML or HTML.

Really, the big competition was BBCode, whose main problem is that it's too much like HTML, and Wikitext, whose main problem was that it's too bare-bones and domain-specific. The big advantages of Markdown are:

1. It's simply more readable. It pulls from how people were naturally formatting plain-text documents meant to be read as plain text rather than pulling from markup languages, so it more closely matches how people want to write documents in plain text. That makes the document easy to read while you're writing it. Asterisks for highlighting is an old convention, so were dashes and asterisks for bullets. Really, it made the asterisk an English punctuation mark for emphasis, which I think it genuinely is now.

2. It was easy to parse and short, which made it popular with Web 2.0 social media. It got picked up by Slashdot, Reddit, and Stack Overflow as "good enough" and "better than BBCode" for user generated content. Nobody liked using WYSIWYG editor boxes then, either. They were slow, buggy, and were often Flash-based before HTML5. They needed plain text formatting options, and BBCode was both annoyingly unnatural to type (just like HTML tags) and a little inflexible.

And nobody wanted to repeat MySpace and just let users use HTML. That was a horrible idea (Samy, XSS, etc.).