If it is not about greed, but why should I be happy to take little and now, when I can wait (hold) and get more? That is somehow a wrong vision of a situation. When we are at school, we dont do test do get C and that is enough, we do maximum of tasks and hope to get A+. Not everyone who hold or trade, do it for sake of greed, because it is never enough. What if there is goal, a final aim, and we just wait for that milestone to be achieved?
For example I have some of my BTC that I have purchased when their price was around 20k. I hold them not because I am greedy and 69k today is not enough for me. I just hold it because 1) I dont need that money right now 2) I set a plan to sell few at 100k.