because the main and only reason why real investors invest in any altcoin has always been to make profit on their bitcoins or make profit on their money so they could buy more bitcoin in its dips. so whenever bitcoin is making big move they dump altcoins to go back to bitcoin and get involved with that big move.
And is it possible that there is an altcoin that can possibly scape from this cycle and how?
for altcoins that exist today? no, not a chance.
but if an altcoin were to be created that is not for the purpose of speculation and trading but for the purpose of being a currency (a coin) then it can flourish individually.
Thanks OP for this.