The second point is specious. How, precisely, do you propose to outlaw private deals, without using universal surveillance, or trained psychics?

Since virtually everyone in the market is long BTC, they desperately want the price to go up, rather than down. This creates an incentive to do OTC (some might say "under" the counter) trades rather than go through MtGox, particularly if the true market rate is less than what MtGox is showing.

However, if it was easier to go short BTC then you'd have people who wouldn't be afraid (and would in fact very much like!) to see the market price go down, and would be more than happy to see declining prices show up in the public order book.

There's a lot of strange behavior in the BTC market and I think a lot of it is because you can't trade it like most currencies or even commodities. You can't easily go short, you can't trade futures, etc. Allegedly MtGox and others are working on those issues, but it's hard to do significant margin and futures trading where everyone is anonymous.

But the sooner they make other forms of trading available, the sooner I think we'll see the unrealistic bullishness calm down.