Apple is a very focused company. They build nice gadgets and sell them for nice profit margins. Everything they do is directed toward that goal.

Entering the search business means entering the online advertising business. They don't know anything about that business; just look at how iAds is working out.

Steve Jobs himself said directly at one of the All Things D conferences something like (paraphrase), "We don't want to do search. It's not a business we know anything about, other people do it well, there's no reason for us to get into it."

That's focus. It's something that's badly needed at Microsoft.