It's because with time and experience, people discover that they hardly to beat the market and get profit consistently and in net, long term, with trading. Then they look at Bitcoin price chart and see history, fact is clearly that if they hold their bitcoins, with a long time like years, 4 or 8 years, they would have been rich now.

In 2016 or 2017, it was not too difficult to purchase 5 or 10 bitcoins that are dream of many Bitcoin investors now. But because it was easy years ago, people fell to trading Bitcoin to altcoins, Bitcoin to stable coins, try to outsmart the market, then they lost most of bitcoins they had. After many years, looking back, they must have insightful lesson to change themselves, from trading to investing.