This.
Markdown took the markup world by storm for a reason. It needs to stay true to that reason. It should not and cannot be all things to all people. Other markup languages exist or can be created for people who have different reasons.
Has there been a discussion here or elsewhere that gets to Markdown’s reason?
I believe the reason is as is stated in the CommonMark intro:
What distinguishes Markdown from many other lightweight markup syntaxes, which are often easier to write, is its readability. As Gruber writes:
The overriding design goal for Markdown’s formatting syntax is to make it as readable as possible. The idea is that a Markdown-formatted document should be publishable as-is, as plain text, without looking like it’s been marked up with tags or formatting instructions. (Daring Fireball: Markdown)
The Prime Directive, so to speak. I would put portability second (the reason for CommonMark’s clarification of Markdown, right?), and then greater expressibility (e.g. supporting tables) third. Greater expressibility must bow to The Prime Directive; we can’t just add stuff willy-nilly. If adding stuff tends to break the Prime Directive, then we have to be very judicious – e.g. don’t add things needed by a a few at the expense of the many (ok, that second Star Trek reference wasn’t intentional, but I like it). If someone comes up with some amazing syntax that supports semantic “divs” and the like while staying true to the Prime Directive, sweet.
[And yeah, I know that some of the greatest Star Trek episodes are where the Prime Directive is broken. But it wasn’t willy nilly. And it certainly wasn’t for self-serving reasons.]