Keep those questions ready to ask the code panel after it has eventually made the spare capacity for an electrical system a requirement.(now it is only a recommendation.See Sec 90-1B)
If the code panel for art 90 ever gets that stupid and I happen to run into a member, I would never ask them, "Why?". Why would one ever ask "Why?"? What reason could they give that would possibly matter? And I really don't see the point in asking questions where the answers don't matter.
Just exactually how would you expect an AHJ to interpret, "
reasonable provisions for system changes"? This is a retorical question - because they can't. The interpretation is subjective. There are no criteria. The AHJ imposed requirements would be all over the map.
Art 90.1.A,B,C are pretty well written. The NEC is absolutely clear that it is for "
practical safeguarding of persons and property", "
essentially free from hazard", and "
not intended as a design specification". It does not require a 100% safe, reliable, upgradeable, system - because no one wants to pay for 100%.
Yes - It is about the money.
You are certainly welcome to a different opinion. And, I'm absolutely okay with your opinion being considered as valid as mine. I do recomend that when you give your opinion, you back it up with examples from personal experience, references, and reasoned logic. Opinion given as statements without these is useless.
ice