[nathankleyn]

Personally I think Markdown got _really_ popular not because it is easier to write but because it is easier to read.

It’s kind of a huge deal that I can give a Markdown file of plain text content to somebody non-technical and they aren’t overwhelmed by it in raw form.

HTML fails that same test.

[singingbard]

People had already ditched writing HTML for years before Markdown came out.

People were just using other markup languages like rST.

Other attempts had already proven HTML to be a bad language for rough documentation. Someone then just needed to write a spec that was easy to implement and Markdown was that.

[epolanski]

Or because it was the default in GitHub with an ad hoc renderer.

[stouset]

Markdown has been extremely popular since far before GitHub existed.

[thrdbndndn]

I'm sure Markdown was already popular, but I agree with the OP that GitHub made it orders of magnitude more popular.

Previously its popularity was somewhat similar to RST.

[epolanski]

Sure, but it became kind of the default with GitHub taking a lead position in code repository services.