For ADN, I believe that stigma is the “Twitter service that isn’t Twitter”. Nevermind that ADN tried to build more than a Twitter platform with their backer program, messaging platform, and authentication layer. Most people saw ADN for Alpha, the Twitter clone they shipped as part of their original funding model.
For me, this is one of the major problems with App.net.
This is the life you choose if you go against the grain and building a platform that isn’t just another ad-based clone funded by venture capitalists.
It's sad for me that such a powerful industry can't evolve without this type of projects.