When I first encountered Markdown, almost a decade ago, I loved it. To say that I now hate it would be going a little bit far, but only a little; I'm awfully close to that.
This change in opinion has occurred almost entirely because, every single time I encounter something that "accepts Markdown", I have to spend some time investigating its documentation to find out what ill-specified sui generis variation of Markdown it supports, and then, usually, also poke at the implementation in order to find out where it differs from the docs. Every single time.
This would not happen if Markdown were well enough specified that developers could just drop in a parser library and be done.
Gruber's currency? Everyone knows he invented Markdown. Everyone loves him for it. And everyone who has ever dealt with Markdown more than once knows that Gruber didn't take it far enough. He's had ten years in which to do so, and he hasn't done it. Now the community, led by Atwood et al., is acting to redress the lack.
That Gruber should be upset by their calling their standardized Markdown "Standard Markdown", when he's had and squandered a decade in which to address the plainly evident need for that very thing, leaves me utterly unmoved. If it bothers him badly enough, let him sue! And we'll all see how well that works out for him. Otherwise, his "currency" would I think gain more from almost any other course of action than further prolonging the exercise in sour grapes which his Twitter appears to have become.
If "Markdown" was just one ergonomic markup syntax among many, then yes, a hostile name-takeover would be completely a dick move. However, Markdown won; there's a bazillion slightly-incompatible implementations, and it's not Gruber's baby anymore. Hundreds if not thousands of people have invested a part of their life into Markdown, either by writing an implementation, using one in a larger product, or just taking the time to learn the syntax.
While Gruber is the original creator of Markdown and deserves respect for that design achievement, the Markdown community is much, much larger than he is and when the two come into conflict, it's not surprising that Gruber loses.
"New syntax, new name. That’s all I ask." https://twitter.com/gruber/status/507651498692849665
Regarding the name: "It more than just suggests control, it asserts control." https://twitter.com/gruber/status/507557595906052096
They may very well end up changing the name, but that doesn't change the fact that this project is basically Markdown++.
Everyone knows Linux was inspired heavily by UNIX, and yet, it's called Linux instead of "Standard UNIX".
I might even have some sympathy for that perspective, if not for the fact that his disinterest in doing anything with Markdown has resulted in such a broad range of subtly incompatible forks, thus complicating many people's lives, mine included, for what strikes me as frankly no good reason at all.
Let him sue, if he likes, or let him keep unfavorably impressing people with public bitching and moaning -- or let him do the sensible thing, if he hasn't yet entirely foreclosed that possibility, and try to walk back his recent bitter outbursts in favor of a public opinion on the lines of "I sure wish I'd had the time to do this sort of thing before now! But I'm glad to see such a strong community carrying forward the idea I came up with so long ago." But to leave Markdown in the dust for a decade, then get all grabby again all of a sudden for what look more and more like the most transparently shallow of reasons, is just churlish.
That others disagree is not an argument for his having abandoned his ownership or rights to the name.
Want to write some Markdown? Do you use vanilla markdown, github markdown, stackoverflow markdown, PHP markdown, a markdown parser with extensions? What we don't need is yet another fork but a standard. Gruber doesn't want to step up to the plate? Fine. The community will. Gruber doesn't like the name? Deal with it.
He gets to decide what the name is, what projects may use that name, and how they may use it.