Those people do not really know what they are talking about, many investors concentrate on how high the price has gone but if you look at the lows you will realize that each year the low has been higher than in the previous years, so in the worst case scenario I see bitcoin reaching a price between 5k and 6k which is still a decent price and depending on the price at which you bought it could still be enough to give you some small profits or at least it will allow you to break even.