Carmack is a legend and I admire his work, but he seems to believe his own legend these days (like a few others big-ego gamedevs) and that can lead to arbitrary preferences being sold as gospel.
Maybe you know something they don’t; it’s actually very likely. But maybe what you think matters actually doesn’t at all and ultimately they’re right.
In either case, they were shipping, so best to listen and be prepared if you disagree.
Not some new OS so you can start making the glasses 2 years later.
Just like when you want to bake a cake, you dont start by designing an oven, or creating an universe from scratch