Oh, I get that, and the fact that most XRP was sitting idle in people's wallets unaware they could sell it helped a lot with the previous bubble.
But here's the thing:
You can still get XRP in large quantities by giveaways.
You also have no idea about what OpenCoin will choose to distribute the rest.
However, you do know exactly how it is going to happen with Bitcoin.
I agree with you, we do know how the bitcoin float will change. And about those large quantity XRP giveaways, PM me please (lol).
And you're right, we don't know how exactly OpenCoin will distribute the rest. What we do have is their pledge to give away 50% (fwiw). And the common-sense expectation that they will do so in a way to maximize long-term XRP value (their explicit profit-model).
The OpenCoin monopoly on XRP is (for non-employees) a bitter pill to swallow. But it comes with advantages (a simple profit-model strictly aligned with interest of XRP holders, aggressively pay developers, bootstrapping new exchanges/gateways with strong incentive, giveaway "faucet" to entice new users, etc).
There might be other "non-profit" ways of developing a next-gen crypto-currency (eg community debate on vague proposals of p2p distributed exchanges in various forum threads). But I haven't seen them amount to anything.