It is not, and not just because of a few idiosyncrasies like C which require context.
Fundamentally, markdown was specified as some pattern matching and English description. The original specification was not done thinking of productions and grammar rules, and you typically don't get there by accident.
I have sometimes pondered how to make a markdown-like language with a simple production based grammar. I have not succeeded and would appreciate any pointers. The criteria being that is has to have something like the minimal intrusion into the prose of markdown.
If GitHub is normalizing comments anyways, I wonder they could have adopted a CFG.
Overall this a step in the right direction but the whole saga is a perfect microcosm of our understructure cranking out pooly-understood stuff which comes back to bite us and cannot be tamed.
