This is true for any industry and it's a basic common sense for anyone but a recent MBA graduate without any real-world experience. There's nothing particularly great or insightful about this quote.
Not really: the practice of installing CEOs without a lot of industry experience is quite common (see Terry Semel). It might be obvious to you, but not to everyone.
Sure, but he didn't have experience as a technology executive, and couldn't call "bullshit" on technical claims made by people reporting to him -- which is Joel's argument for why this sort of CEO isn't often a good idea.
Not to veer off into politics, but the Bush administration would seem to be an existence proof that at least some part of your statement is incorrect. (Yes, I realize Bush has an MBA.) I've run into this attitude fairly often, and not just among MBAs.
