Second, Bitcoin is supposed to be a currency, but it's actually a speculative vehicle. If Bitcoin were a successful currency, there would be many merchants using it for small transactions, with perhaps some speculation on the side. In practice, the speculation dominates. This is the real problem with Bitcoin.
You are correct. The excitement in this teeny, tiny micro-community is due to the anticipation of bitcoin's use as a currency. There is risk in speculating that it will be adopted as a currency but there could be huge payoff too! Your criticisms of bitcoin seem based more on analyzing charts than on appreciating its fundamentals.
Bitcoin is the first of its kind.
Actually, it's the third or fourth. Digital era predecessors in pseudo-currencies include Beenz, DigiCash, and frequent flyer miles. Going back further in history, look into how the house of Thurn und Taxis got rich after inventing postage stamps. (They also built and ran the postal system).
The main new thing about Bitcoin is the generation mechanism. DigiCash was equally anonymous, and had a comparable anti-double-spending mechanism. But it used a central "bank" to keep the transaction list.
It's also an illusion that Bitcoin isn't centralized. Some of the policy, such as transaction costs, is embedded in the client. The constants that drive the coin generation rate were set centrally at launch, and are embedded in the early coins. Those locked-in policies favored early adopters and set a ceiling on the number of Bitcoins which is not that far away.
The current model for Bitcoin exchanges is over-centralized, because the "exchanges" also act as depository institutions, and are sluggish about handling withdrawals. In the real world, a broker can execute a trade on any exchange, and the exchange can't tie up funds. Even limit orders are cross-exchange now; this is done through a "consolidated limit order book", where all the exchanges work off the same limit orders.
This isn't a magical new development. It's a minor advance over previous technology.