Good points you make!
Perhaps we just learn by theses huge swings and if the next high hits, we switch some of our profits in Fiat and sit it out for the next attack to profit from it.
The question is only when and not to enter too early.
Otherwise longterm hodling or better investments in quality coins (Dash, Steem, Sia, Waves, Iconomi, Ripple and probably Tezos) is a good strategy as well.