This is a bit of an assumption too - yeah there will be a lot of short term view speculators involved, but perhaps there is also a lot of money coming in from people that see the potential value of the technology as a store of value and plan to buy and hold (like gold)
Bitcoin will lose value when owners will start hoarding their coins without any usage. Bitcoin value is strongly tied to the amount of transactions because that is what keeps faith in the format of value. Without transaction volume, bitcoin will just fade into a list of empty promises. Gold is not like that because golds value is less speculative then with BTC. Gold can be used in electronics or apparel and this gives real value besides speculative value to gold.
The real value of bitcoin and cryptocurrencies in general is the ability to transfer funds safely and efficiently. Holding coins alone is just a big waste of an good value transfer system.