No OS should steal focus, Windows absolutely is guilty of it.

When you launch an application or open a dialog, you expect the new window to "steal" focus. When you close a dialog, you expect focus to go back to the main window. If it didn't, it would impair usability.

So how would an OS decide when "stealing focus" is allowed and when it is not?

Like, I'm frustrated with it too. I hate when an app pops up a dialog while I'm typing and my next keystroke dismisses it and I have no idea what I've done. But at the same time, I'd hate to have to manually switch focus to a pop-up dialog every single time before dismissing it with Enter or Escape too -- that would be way too annoying in the other direction.

In my experience, shipping a product as polished as Mac OS X 10.6.8 Snow Leopard requires a painful level of dedication from everyone involved, not just Quality Assurance.

As long as neither the New York Times nor the Wall Street Journal writes about how bad Apple’s software has gotten, there’s even no reason for them to think about changing their approach.

The drama surrounding Apple’s software quality isn’t showing up in their earnings. And at the end of the day, those earnings are the "high order bit," no matter what marketing tries to tell us.

How?

How do you reproduce something when you have no idea of the cause and it's not happening on any of your machines?

And remember they don't have just this one unreproducible bug reported. They have thousands.

If you have experience writing software, you're going to end up with a lot of unreproducible bug reports. They're a genuine challenge for everyone, not just Apple.