The problem is that people never learn that once bitcoin drops just buy, you will likely never lose in the long term. Buying bitcoin at $3k was an opportunity to win fast ~$1k per 1 BTC (without counting who already bought less than $3k in the previous years).
It is true that if you take the opportunity to buy bitcoin when its price is very low the chances that you will make money in the long term are very high, but you seem to forget that most people do not really care about the long term, they are only interested in getting profits in the short term, that is why they panic they see the price of bitcoin dropping a little bit and they decide to sell for a loss even if deep down they know the market will recover.