Because when new bull run will arrive there will be new shitcoins and your shitcoins will end dead or delisted from exchanges which can lead to 100% loss.History is always repeating.
5,5 years old chart:

Surprisingly some coins from this chart are up from then but volume on exchanges is low,so holders of these coins are truly bagholders.
The history of the market will always be like that plus the uncertain time.
Yes, they look like rising solely to mislead users who don't understand and they mean so that shitcoins are considered superior to other coins including the main crypto like bitcoin, but actually they are attackers for bitcoin.