Of course you are right. The Prisoners Dilemma is an oversimplification but there is an aspect of it. The problem is there are people who are even hoarding the Bitcoins they buy regularly and spend nothing.
Although I have no idea how many, but by observation on volatility it seems significant.
I agree. If I were to speculate on the causes,
I'd say that to a great extend people are holding on to their coins not so much until they are worth a fortune but until there is something useful they can spend them on. You know, there is only so many alpaca socks you really need
The situation seems to be better in the US, but for the rest of the world, the amount of goods and services that can be purchased for Bitcoins and that one really needs is still rather limited.
Many people seem to happily pledge to buy Reddit gold, donate to the EFF or Wikipedia if only they could use Bitcoin for that. Sure, some probably do so in part because they simply want to reward Bitcoin acceptance, but most would probably genuinely like to help these organizations and for any number reasons prefer not using credit cards or PayPal.
Until people find a better use for their coins I can not blame them for holding on to them or even enjoy trading/speculating with them a bit. In any case, I don't really see hoarding as a long term problem of Bitcoin.
I completely agree with that.
As for the rocket analogy:
I think we are still in the blueprint/prototype stage...