"Is it a poison that will end the bubble of tulips" Or "the beginning of something big: the currency without a government, something necessary and imperative"
It may be both. It is important to make a clear difference between actual cryptocurrencies and blockchain technology.
Blockchain technology will prevail, actual cryptocurrencies may not. I am not sure if a cryptocurrency not controlled by neither goverments nor banks will keep being used for legal transactions.
I hope that your tought will be right, because now we are under control of bank and goverments...