This debate is about desktop and server processors. You are imagining there is a market segment, worth caring about for non-niche companies like Intel, of non-hackable systems with no network access that use high-end microprocessors, but it isn't so.
Most relatively complex systems that use deluxe microprocessors and could be air-gapped are accessible for convenience instead, and more extreme actually inaccessible systems are likely to use different, specialized processors.
Why do you exclude all single-purpose networked servers? e.g. why wouldn't it be reasonable tradeoff for a private compute cluster with a limited set of applications (or even just one), systems running really dumb services, ...?
Most relatively complex systems that use deluxe microprocessors and could be air-gapped are accessible for convenience instead, and more extreme actually inaccessible systems are likely to use different, specialized processors.