I'd like to add what we could call maybe a third school of thought which would be that Apple wants to make know and use their browser to the largest community of potential future mac developers possible. Even if you have never heard of mac or safari before, you can take a look at Safari on Windows. And maybe you'll like it. And maybe it could happen you will start developping applications for mac or even websites supporting Safari. In both cases Apple wins. And now multiply by developper community all over the world.
Nope ? ;-)