Is it possible that these companies feel they have more to lose by missing out on AI than by taking on debt? Or that they genuinely are in a race to superintelligence, which easily justifies this debt and far more?
When I worked at Apple, I remember seeing the commentariat insisting that <project> was bound to fail, that we didn't know what we were doing. When in fact extremely competent people knew precisely what they were doing. Of course, the commentariat were wrong and I'd wager most of them use what I had a part in building. The same story tended to repeat across my subsequent jobs in big tech. All this seems quite similar to me.