I think there's a difference between Bitcoin and Dropbox/Twitter. Even if you were skeptical about the latter products at first, with the benefit of hindsight, it's easy to make a retroactive argument for why they made sense (better usability, better network effects, etc).
But with Bitcoin, even with the benefit of hindsight, I still don't get it.
But with Bitcoin, even with the benefit of hindsight, I still don't get it.