Cryptocurrencies pay no dividends and have no "destructive" demand. So they have no base price to anchor the speculation, even remotely.
They have a fundamental value which is described by PQ=MV.
Destructive demand in this case means savings. Dividends in this case means deflation.
Deflation means change in price, so that is not "base value" but the very unknown variable that the market has to define.
Savings is not "destructive" because the bitcoins saved will be traded again depending on expected price. Indeed every bitcoin is always someone's "savings" except for an instant while it is being traded.
(Perhaps one may consider that bitcoins are "destroyed" temporariliy while a transaction is awaiting confirmation from the net, if they cannot be traded or used for commerce in that interval. From that "consumption" and predicted volume of commerce one may be able to compute a "base value" that does not depend on speculation, assuming that Bitcoin will be the only cryptocoin in use. However, the volume of "consumption" depends on the speed of confimation. Is that predictable?)