While I certainly agree that there is some "Tulipmania" going on, I think that there are some very disruptive applications to the technology. A few examples are
1- The embedded security due to decentralization (so no need to trust yourself or others). This has some applications for cyber contracts between applications owned by different entities.
2- Another use of this is to remove middle men in a variety of transactions. This was something not entirely possible in the current systems (in which middle-men are usually the highest cost of transactions).

I think that if these technologies continue to be used for speculation the bubble will certainly burst, however if the technology is used for it's intended purpose (which was to conduct transactions) it has the potential to be very disruptive.

Lastly, I believe the powers that be are most likely involved in creating the bubble as they have a huge incentive to make this fail, so that they can then insert their own version when they are ready.