I think there are 2 major groups of people who hold altcoins.
1. The true investors, who know that they can make a lot of profit from an altcoin if they hold it for long periods of time (like the early Bitcoin adopters did).
2. The ones who got into this crypto craze in dec 2017, when the price of bitcoin peaked, and so did everything else. For those who both just before the market started to drop, selling at any point before reaching that price again, would be a loss.