I don’t know the answer to these questions, but given what I do know about the A4, I suspect that the reason is twofold. First—and this is purely my supposition—Steve Jobs just loves secrets. The A4 no doubt gives him that special, “I have my very own custom SoC that you don’t know anything about” feeling, and if we’re honest with ourselves, wouldn’t we all love to know what it’s like to have that feeling? I know I would.
Yo es que siempre me imaginé a Jobs pensando eso.