Lack of Quality. There is precisely the reason we have distros like Manjaro.
We need options and I am not against it. But every option needs to be unique and different. For ex: we have GNOME and KDE, both are good options for a DE, but they are unique. On the other hand we have Manjaro and Elementary and Garuda and others, all of which are same. ( With a few wallpaper or some kernel flag differences)