It depends on what the person had in mind for their investments. Some people have a specific price they're waiting for to take profit, so when that time comes, I see nothing wrong in taking profit at that point. I don't believe Bitcoin is ever going to have a peak. I mean a price that it can't get past, not in the next 50 years at least, in my opinion, so when will be the right time to take profit? The right time for another person may not be the right time for me because we have different things in mind when we invest.
As long as it was a calculated and thought-out time to take profit, I don't see a problem. The problem is when they take profit out of FUD or out of panic, and even at that, I don't entirely blame them. You can't be certain which way bitcoin will go, and if it goes down, you can't tell how long before it gets to another ATH again.
Well spoken, your right time may not be my right time as everyone has their own choice to make. There's never an ultimate time to sell because Bitcoin's price will keep changing over and over again and everyone has different target, there are investors that sold when Bitcoin was at $100k and as long as they have made their profit to reinvest again I don't see anything wrong with that and even if new investors buy at the current price now there's still a chance that they will make profit in future.