He is right in the sense that we do not need another distro. He says you could customize linux a lot in the past and he celebrates that - and system76 is customizing their computer.
He is right that the money wpuld be better spent somewhere else but system76 is trying to sell laptops and they do so by distinguishing themselves from the rest by creating their own de.
Cosmic looks like KNOME and I won’t use it. But I don’t use cinnamon either and there are people who like it.
I don’t like that there is another de but it drives competition which is good. Maybe GNOME has to give their apps more functionality now.