I understand, and I partially agree with you.
Still, in an age where there are cameras everywhereand in an event that Apple itself was broadcasting the keynote worldwide (I watched it in real time right here, in Brazil)there is no such thing as an event disconnected from marketing consequences. Especially in Apple's case.
Also, the same message could have been conveyed to all the developers in attendance, but away from the scrutiny of the Internet at large: all it would take is for Apple to spread it throughout the event and throughout the week, in the several presentations that will offered. I like Jobs' assertion that "For Apple to win, Microsoft doesn't have to lose". It's quite a powerful notion, and a very true one, too.
Also, ignoring your opponents in key moments always sends a more potent message than acknowledging them.
Oh, and also there's that old P. T. Barnum quote, "as long as they spell my name right", testifying that there's a lot to be gained both by Microsoft and by Google (mentioned through Android) because they were both mentioned by name in an Apple event.
When I see other companies bashing Apple, the first thought that comes to my mind is: "you have to be pretty afraid of Apple in order to mention their name in YOUR spot". Thats what people keen to Microsoft and Android are left thinking, I bet, after they see those pie charts.
