> ...OS X 10.10's share of OS X users....
I think you meant 10.9.
You're right... I shouldn't have singled out Mavericks, because OS X took a major hit across the board. (Hmmm... I wonder if the entire 10.10 percentage is at the expense of 10.9 or if the beta testers are in the stats twice?)
You say that "this kind of retrograde motion hasn't been uncommon", but can you think of any reason for a 9% across-the-board swing in one month? That's a pretty big hit! I can see statistical anomalies, but this one seems unreasonably big.
