Haven't used this much lately.
Some random reasons perhaps why:
I was hoping this would be good for sharing brainstorming-in-the-shower kind of stuff. Unfortunately a) writing conflicts with brainstorming, b) water conflicts with electronics.
it feels too isolated. I wish others could add thoughts to my streams.
actually, I wish others could annotate/edit my cards inline.
in realtime!
without any strong social aspect, it's a bit distasteful to me to host essentially static pages on someone else's property
I'm imaging something more like a mashup of Etherpad, Federated Wiki, Github (and/or its Gists) with a visual design and posting interface ecosystem tailored towards some motto like "Thinking Out Loud, Together"
Instead, right now I feel like I would just be setting up a separate commentless microblog for each of my hobbies — which is actually antithetical to my goal of writing quicker, shorter, more frequent posts about everything I'm working on, on my own site.