Most people who got burnt buying into ICOs and other coins in 2017 are already out of the market and even though they might of smartened up they probably moved away from crypto-currencies.
However a new herd of investors will arrive when the FOMO starts again soon and they will buy anything pretty much. I remember when every single coin on Cryptopia was pumping back in Q1 2018 because people wanted to 100x their BTC by buying the next best coin.
People will say that BTC is too expensive and rather buy some coin worth a fraction of a penny because they will think it will be the next BTC or ETH. And they will get burnt like everybody did in the past.
So no.... people never learn.
Definitely yes! Some of the investors are easily exhausted. They do not have enough patience to stay in cryptocurrency. They leave when bitcoin as well as the market goes down. They say that BTC is expensive but when they pulled by FOMO, they buy bitcoin even it goes up 100 percent.