This happens all the time in market . Any new controversy or fork leads to the downfall in the bitcoin value but that does't mean that this is going to affect the bitcoin's existence . Bitcoin ha survived many hardforks and many such situations in the past and have earned an even more value after that .
Bitcoin is not going anywhere . The BCH is already starting to loose its value and bitcoin is rising on the other side . Any other altcoin cannot shake bitcoin so easily overnight.