It's been three years since the thread was made and there's truth in what he said about Ethereum. While the discussion is about $1200, Ethereum as it pumps again didn't passed on its past ATH.
And today's price of is even less than the price that was indicated on this thread.
Even more interesting is the fact that people that purchased Ethereum 2018 at the high price had to wait for 2-3 years to even breakeven. People only fomo when it is high. I don't know why they like buying highs only to sell lower than they bought. It would be better to do it in reverse. That is to buy low and sell higher just like OP said in 2018.
That's the usual reaction when a coin goes into high price. The FOMO will be found everywhere as if the trend will never stop and those who have bought at high of $1k-$1.4k price of Ethereum probably have sold at loss. They can't contain the pressure and they have to stop loss and that's the usual mistake of investors especially the newbie investors.
Stop Loss is something that investor need to do, its better to lost some than lost it all, isnt it? and maybe the one that do that already buy more when the Ethereum price lower, so they minimize their lost.
So in my opinion stop lost isnt a mistake, its part of investment strategy.
But that stopping of further loss has different situation for many of them. Some were good to stop loss before it has finally crashed until the end of that year.
And some did just stopped loss when it's finally a total loss for them and that has finally decided them to end the game which is very unfortunate.