Bitcoin might fail but it's not a waste. It's inspired a whole wave of alternate crypto-currencies and gotten the public excited in general for them. And wallet and exchange service and a general ecosystem of services have sprung up that could (and do) support any virtual currency. That's all value that can't be lost at this point.

As far as wasting people's time and effort, my hunch is that most people are devoting their hobby time to this and in the process learned a little bit about economics and computer hardware. That time would have probably been spent on computer gaming or aimless web surfing anyhow.

Bitcoin may end up a big flop[1] in the end (who knows) but without trying it there's no way to know, so expending all of this time and effort isn't wasted.

Similar to scientific experimentation; the outcome, regardless of success or failure, is useful in itself.

1. For the majority, there are obviously some people for whom it has been a roaring (financial) success.