It's too relentlessly public.
It's clearly been designed to minimize all interaction friction - just using the app now generates activity which can be consumed by others and I imagine the end goal is to make it addictive as all hell.
But that's exactly what makes it so creepy.
I really dislike how much it shares automatically. Reporting whether I've read an item is incredibly hateful; privately browsing/stalking is the number one virtue/sin of social networks.
There is no way to delete comments or posts. Worse yet! I intensely dislike how there is no way to delete location checkins. No one has yet to tag me, but is there a way to untag yourself form photos or locations?