I think the biggest thing is that the sad centralized Internet has stability. 

You have to be *really* committed to set up your own status net instance (which I would never have managed but for serious amounts of help).  Although I give great credit to those running self hosted StatusNet instances who have invited others to sign on, if you don't personally know or trust the people running those instances, signing on could prove to be an even greater risk to your privacy than joining Twitter. 

I look forward to GNU social stepping up because it will make it easier for ordinary folks to join the distributed internet.  There are plenty of free software supporters who are not tech gurus.

I do have to say, I would never dream of suggesting anyone who is not a devoted techie to sign up for pump.io until the bugs are shaken out.  Maybe a year from now?

Sad to say, rather than being a service, I fear Identi.ca is more of a petrie dish.  That's a hard place to be if you're not a dedicated techie or a software developer.