Twitter's problem is their continued refusal to recognize themselves as a platform. It's probably too late at this point, but I don't think they have anything to lose.
Twitter is what you curate it to be. To me, Twitter is kind of the publishing platform Linked In was trying to build. Smart people posting interesting links (to their posts or others) and people discussing.
However since Twitter is what you make Twitter to be, garbage in garbage out. I quit Twitter for about 2 years but then unfollowed every account and started fresh. Now I use it all the time, way more than Facebook, etc.
At the moment, and since just after I quit Facebook, Twitter has worked for me regarding how I communicate and consume over such "live feed" social media.
edit: before anyone notes it, I'm just thinking about offering it and the relative value of each on a per user basis vs ads. Yes, it would churn their userbase out of existence.
People use Google for search. People use Facebook to connect with friends and family. Who needs a Twitter account aside from journalists and attention-seekers? my grand mother doesn't need a twitter account. Nobody cares about her cooking a chicken or planting cucumbers in the garden BUT her closest relatives. And there is already Facebook for that.