I think the root cause may be covered in this SO Question [1] which fixes the problem on many sites by re-ordering font inclusion list so Chrome+Windows picks up the right one.
1 = http://stackoverflow.com/questions/4060607/font-face-anti-al...
I know they're not common yet, but they will be someday. Designers often use the latest (Apple) hardware, so what looks good on their screens may not look good for everyone else. In some ways I see this as a positive—it helps push the industry forward—like PC game developers who require the latest $800 video cards for the best experience.
Also, Kleenex is a brand name but if I ask for a kleenex people know what I mean.
Edit: woops, the Adobe javascript was getting blocked by Ghostery.