*Bitcoin drops another 20%* - "I'm not buying. bitcoin is dead"
*Bitcoin reaches the price floor, then rises slowly for months an months* - "I'll wait for the dip"
I know people who are doing it this way:
-20%, I'll wait!
-70% I'll wait it can still go deeper.
-85% at -90 I'll start buying
-Bounces back 20% - It's not confirmed yet, I'll wait a few weeks, if it doesn't fall I'll buy.
-goes up another 20% - now it's too expensive, already 40% from the bottom, not worth it.
I also know a guy who once bought Bitcoin when it fell from 1k to $500 and then it went down to $250 and he sold with a 50% loss...This is the best example I can imagine to show what mistakes can a Bitcoin investor make. I think many people who bought BTC at around $40k are selling now in panic. In fact, they are doing the same mistake as the guy in your story. Panic has never been a good adviser, has never helped in any situation.
As for those who's waiting for even deeper drop to start buying. Well, read the OP, I guess.