They should concentrate on a wide variety of features and make it modular. That way, I could download a build with bold, italic, and spoiler syntax. Or, someone else could download one with only lists, strikeouts, headings, and math formulas. When you're missing even one feature, people go elsewhere.

Lastly, why is everyone hellbent on following the original syntax like it's the word of God? Anytime I hear someone complain about an issue in Markdown, people point to the 2004 syntax and how it's true to spec. Users don't care, they want something usable. I'd be happy if someone creates a completely new spec, and I never hear the word Markdown again. I'm tired of the same issues being passed down.