Sure, bitcoin may be a bubble. But by causing this year's sensational increases in the value of an electronic commodity that can't be used for much more than speculation, bitcoin investors are raising the visibility of the technology behind it, driving more people to work on improving it, making it fashionable and thus interesting for financial institutions and governments.
https://www.bloomberg.com/view/articles/2017-11-28/invest-in-bitcoin-even-if-it-s-a-bubble