The fact that you would bring up a hosted service that is extremely complex and costs tons of money shows that you don't understand where I'm coming from at all.
Markdown is not some amazing patented invention that John Gruber is entitled to perpetual dictatorial rights to forever. It's a simple derivative idea. It's out there in the wild and people make tremendous use of it, but none of this use costs John anything, and it's successful on the backs of many implementors, not just Gruber. It's all fine and good to say design a competing "service", but people do do that, and all it does is lead to yet another variant which further exacerbates the problem.
To be clear, I'm not saying John owes anyone anything. He's free to do or not do whatever he wants, but so are other people. Precisely what courtesy do you think he's due if he refuses to act in any reasonable capacity as a steward?