The acutal problem is that the web app designer was incompetent enough to only design for one platform. Apple holds zero blame for that, and as a Mac fan [that does MS and Linux too], I find people who want to rant about thier dislike for Macs at every mild opportunity to be a bit nauseating. And when the explanation is something as thin as, "that's it, plain and simple," I become catalyzed to defend reality.
I'd venture to guess that if one tried to go through that system with Linux, one would find it wouldn't work either.
Sorry to further the OT topic,