Your average currency pair moves less than 1% on almost all days. Moves above 1% are rare and days with moves of several percent are extremely rare and occur a couple of times a year at most. BTC, on the other hand, may be worth anything from 250 to 60 USD a day. That is the reason why BTC as a currency is of little use. You cannot do serious business with something like this unless you immediately hedge all of your exposure. In a larger organisation that would be impossible and, on the other hand, only means that someone else is holding the bag for the next crash.
BTC is driven by little to no fundamental data. Its exchange rate is subject to pure mass psychology which is why it repeatedly goes through boom and bust cycles. This is not going to stop unless something like a real BTC economy of non-trivial size develops. But I think it very unlikely for this to happen for the aforementioned reason of volatility and the fact that BTC is by design deflationary. BTC's deflationary properties would choke off any such economic system that is based on this crypto currency.
All in all, I am of the opionion that BTC is an interesting experiment and a case study in speculative behaviour. The difference compared to former manias (see [1] for historic examples) is that in BTC the process plays itself out at an extremely accelarated pace. Maybe this is even what the creator(s) intended. Maybe they created a purely electronic ecosystem of speculative behaviour to be able to study and better understand the phenomenon of financial bubbles. This would certainly explain the 'Satoshi' entity's non-interference.
[1] http://en.wikipedia.org/wiki/Extraordinary_Popular_Delusions...