2) The hardware issue was addressed in 3. Also, I don't follow, what do you mean by "the costs of supporting Chrome/Firefox are very incremental?"
3) That's a fallacy, actually. You're both proposing and confirming that "No one likes running VMs on their boxes because it still crawls". I, for one, run Windows XP VMs on my 4GB Core i3 iMac with no burden on the host OS at all. Some people might suffer with it? Yes, but some people could try tuning their setup for their needs.
Anyhow, we both know that the kernel of your argument is the first topic. I could convince you that the benefits outweigh the costs in 2, 3 and 4. But if your mindset is focused on giving the very same experience to every agent that can reach your app, or giving no experience at all; this argument is already over.
Also, saying that Apple does X or Y means absolutely nothing. Even if your company were almost exactly the same as Apple in every competitive aspect, nothing can assure that copying its culture would also lead you to a successful path. Actually, I believe history tells us the opposite.