The market that Microsoft directly competes in (using IIS) has never been anywhere near the shared hosting space.
The purpose of collecting these stats is not to find out how IIS is doing in it's target market, but instead to find out how popular web servers are.
If I were to suggest removing all non-Free OSs from the statistics (since one could claim that as a Free web server Apache doesn't compete there), then you'd see totally different numbers aswell, and that would just as deceptive.
No, no-one suggesting removing non-free OSs. However the grandparent post suggested removing shared hosting, since IIS doesn't compete there. This would fudge the stats in IIS's favour, in the same way that removing non-Free OSs would fudge the stats in Apache's favour.
The purpose of collecting these stats is not to find out how IIS is doing in it's target market, but instead to find out how popular web servers are.
If I were to suggest removing all non-Free OSs from the statistics (since one could claim that as a Free web server Apache doesn't compete there), then you'd see totally different numbers aswell, and that would just as deceptive.