I think its greed that drives such behavior. Take the current situation, for example. The price is around $20k, which is more than 3x below the ATH. If you believe that Bitcoin will recover, just like it always did before, it's reasonable to assume that if you buy now, you can expect a 3x profit, if not 4x-5x because the new ATH is normally higher than the last one. That's some wonderful long-term profits which are very likely. But no, people get greedy and start thinking how much more it can be if Bitcoin goes down even lower, in the end not getting anything out of it.
Those who don't take this opportunity to buy more bitcoins will regret that by the time the price starts to increase, you will be late to buy and even if you can buy it, you probably won't be able to get the low price.
People will start buying when the price starts to increase and tend to hold it if the price drops back down and just sit back and watch the price go up and down below the price he bought.
But if he's already decided to buy at every price bottom, then there's a chance he'll keep buying if the price goes down further.
This needs to be analyzed further to find the right price so that we can buy it and it's okay if we can't buy at the lowest price because it is very difficult to predict when the price will reach the lowest price.