I assume he is afraid of people with lofty high level ideas in charge of pushing out products for the metaverse that are just not fun or even usable because the

I assume he is afraid of people with lofty high level ideas in charge of pushing out products for the metaverse that are just not fun or even usable because they started top down, missing end user detail, while Carmack would start implementing the details instead and maybe the high level stuff emerges, maybe not, but at least you have products users want to use.