I sort of agree. App.net lacked value at launch because of the way it intended to build value - through apps on it's platform. That's inevitably slow just when you need to build take-off momentum, and there is no way to "prime the pump" except by throwing money at the problem and hoping you get the right apps.
Moreover, Twitter has a problem with churn. It's free to start, but baffling for many, and troll-infested if you stick around. All ad-supported social networks have that problem plus the invasiveness issue.