I partially agree with this 78%. Probably people think that Bitcoin value will raise during next years and try to store a little treasure in their wallets.
Actually, Bitcoin are almost useless. There aren't big merchants accepting Bitcoin and if you want to spend them, you don't have a lot of choices.
We all hope that Bitcoin value will raise, so, we don't want to spend them by now. But, why do you keep your Bitcoin FROZEN under digital mattres? Why not to INVEST them?
I can suggest you a secure, fast and very profitable investment: http://www.links-pyramining.com/pyramining
Firstly, your Bitcoin will be stored in a safer place than a normal user can do with his bugged pc ;-) Then, during a time around 14 months, you will have all your Bitcoins back +10%!!! Without any hardware investment or power consumption.
Investments like this, not only will increase your wallet, but will increase Bitcoin volume traffic and so Bitcoin general value. It's a double profit!