Well, investing in shitcoins is definitely bad, but I really don't see a problem with trading shitcoins. Also, why is it a waste of time? If you can make more money off it to increase your bitcoin holdings, then what's the problem with it? Trading doesn't automatically mean taking part in pump and dumps.
He already generalizes it that's why he do proclaim overall that investing or making yourself involved to shitcoins is bad without even recognizing the advantage on having an alternative
ways to earn Bitcoin more.
If you do just trade smartly and secure profits within even on slight move then you are still good.