Who cares if what we do is perceived as being useful. "Useful" is a matter of opinion. I find having Bitcoins to spend quite useful. I found burning out two cpu's while folding@home not quite so useful. Wanting to contribute to the greater good is all nice and dandy, but i see no need for it here. You want to help the world? find away to cut the population in half without killing anyone. that would be a help.
Wow thank you so much for that inspiring sentiment.
Any zero-use commodity in history eventually converted into a zero-value commodity. There have even been commodities with negligible use, such as tulip bulbs, that eventually had a collapse in price. They were useful in so far as they were transportable(in much the same way that BTC are easily transferable over the net). At the time of Tulip Mania, there was quite a demand for forms of wealth which could be loaded onto ships, transported to eg. New Amsterdam in the new world, and then converted into more useful assets like farmland. However, eventually the market became saturated as the production of such zero-use commodities proliferated. People were 'mining' tulip bulbs left and right, a good portion of the Dutch economy was geared towards growing tulips! How silly of them. Of course they argued that these things were great because they looked nice in your garden, thus had value, and more importantly they had EXCHANGE value- so why argue with it?
Eventually people who invested heavily in tulip mania lost everything.