That's mostly all good and fair. I don't have any data to contribute. But the I think my fundamental point is good:
PC market share as defined by analysts is reflective of the market that Microsoft is pursuing, but it is a large superset of the market Apple is pursuing.
You say this is silly to point out, but you're leaning on circular logic. You take "the market" as a given a priori, but the truth is that the market is defined a certain way, and that way is very unfavorable to Apple (and that's without even getting into the whole profit share vs market share question).