If you actually believe what you're saying, then short it[1]. If you really think that the practical value is non-existent, then put your money where your mouth is, and take out a short.
This isn't some academic theory where the best you can do is throw tomatoes at it, and ridicule it from a distance. This is an economic theory, where if you are correct, and everyone else is wrong, you can profit significantly from it.
Maybe once you're faced with actually taking a stand on a belief like this, you'll come to understand why cryptocurrencies are beginning to dominate the global economy. It's also totally possible that you're right, but I think it's far more likely that you just like to ridicule things you don't understand because you get some sense of power from shitting on people who you consider to be beneath you.