There is a very thin line between the greed and the risk in this case. The reason is that if you do not take profits at certain key levels then it is highly likely possible that bitcoin may not move further and you miss out taking profit and holding your coins for another bear market.
I wouldn't call it a risk nor I will call it a greed but I will call it a sensible way of exiting at the top. No one can call the exact top, it's all speculations.
This is the most accurate take. Bitcoin cycles are more or less predictable. There's nothing wrong with trying to take profit somewhere near the top. Not everyone can do that though. That's why the safest bet is to be eager when buying, but not as eager when selling. Everyone has a different risk perception. Someone who believes Bitcoin's price will rise a lot might seem greedy to the average person. But no one's opinion should influence your decisions. In the end it's you who makes or loses the money, not anyone else.