+William Brine +Zak Kaufman
is right. You may not PERSONALLY like it, but you have to separate your personal feelings from the realities of the situation. The whole reason Twitter gathered such a following was because there are so many great applications that integrate with it. G+ has none of these.
One example - when I check in on Foursquare, it also checks me in on Twitter and Facebook - even though these services have their own check-in, they also allow third parties. G+ does not, so it misses all of my check-ins.
Another example, when I post an update with my mobile phone widget (Samsung), it goes to both my twitter and Facebook, so I don't have to run two different programs. It DOES NOT update my G+ because developers have no ability to do this integration.
Finally, even look this ShareCompat API, which is in relaity a giant hack to work-around lack of a write API. It is very clunky for a user, because they now have to enter their comments TWICE, once for Facebook / Twitter, and then enter them AGAIN in this G+ pop-up dialog. If you want to see how clunky it is, just try it out in Pulse, sharing to all 3 services.
The simple reality is you are never going to wean people away from Facebook if they have to ALSO ditch their favorite app and use some other thing - that is the LAST thing people want, is to have to do TWO status updates. If you want to get people to switch, then allow the TweetDecks and the Plumes and the Seesmics of the world to let people post to BOTH networks at the same time, and then maybe they will gradually switch over.
As a developer the lack of a write / post API is very perplexing, because it would be so easy for them to implement. I have to think that the only reason they have not done so is some form of political reason.