I didn't say Bitcoin itself is a scam, only that the market is so tiny that a single player could easily manipulate it. And if someone can, someone will. And while I see Bitcoin's legitimate use cases, few (very few) people are using it for actual trade. The market seems purely speculative, with no underlying Bitcoin economy to stabilize it (save possibly the money-laundering business).
I agree that the market is largely speculative. But I think the speculation is mainly very long-term speculation - so people predominantly want to get more bitcoins, or they want to hold them. This will tend to drive the price up.
