Sometimes, movement of these coins can be so fast that if we take our eyes off the trading platform within 1 minute, that one minute you see could mar our trade, and you cant tell me that a trader will just focus on the PC without standing up at all, at some points, we will stand up to take a break, use the gent and may go take a sit of cold drink from the fridge, the time you decide to do that maybe when the market start falling drastically, and only stop loss could save you against terrible damage. I feel sometime that It is only people who have the intention of being greedy that usually avoid using stop loss/take profit.
This is especially true if you are a short term trader and you are trading low market cap coins, any moment in which you are not watching the markets and you are not using a stop loss could mean devastating losses, however if you are a long term trader having a stop loss that sells automatically if it reaches that price is not as critical since it only takes you a few minutes to see how your positions are doing, however I will only recommend this to experimented traders since it is easy to make mistakes and there are many things worse in this market than getting out of your position with some small losses.