1) It may well be a dumb thing they do, but is this really "why big companies keep failing?" There's no real examination of this causal assertion which seems central.
2) Is it really the "stack"? That is to say, do people really assume that just the layer above them is trivial? I see engineers all the time assume that basically everything they don't understand is trivial. For example Elon Musk's famous assertion that the hyperloop is "Basically just like an air hockey table. It's not that hard". Well in turns out air hockey pucks don't need to transport people, g-forces aren't important for air hockey versus not murdering your passengers is quite important for a public transport system. Air hockey pucks don't need to breathe versus people do which makes the vacuum part quite critical and challenging especially since you have to figure out how to get people in and out without rupture. To think of it as like air hockey you are assuming that all interesting/challenging parts of the problem are trivial. To be clear: I think that this hubris is basically essential for innovation. I really don't think people would ever innovate if they worried too much about every small detail of things, but this is why a large proportion of experiments by everyone (big and small companies alike) fail. I don't think the layer above you in the stack is the important part here and the article doesn't examine whether that characteristic is important.