I've posted that on HN because Bitcoin is not just some commodity, but a useful technology that allows you to do many interesting things besides payments. See http://blog.oleganza.com/post/42262765318/direct-use-value-o...

If I recall correctly, tulip bulbs are a useful technology that allow you to create beautiful flower gardens.

I don't know why you're being downvoted. This is a very valid point. We've had speculative bubbles for as long as we've had financial markets - I don't see any reason why this one should be different.

I'll always up-vote these comments, I have invested a small amount in Bitcoin but am fully aware the whole thing could tank and never return, I consider it to be an interesting experiment for myself. People do need to know how risky this is though.