"Tap to zoom" is a patent by itself, as stated in the article.
Protecting "Slide to unlock" seems justifiable enough to me. But "tap to zoom"? That's like patenting a key bind. Of course you're going to tap it; it's a touchscreen! Duh!
Also, just because they patented it doesn't make it THIER work (talking common sense here, screw the flawed manmade laws). If someone other people have implemented it first, but Apple's the one who patent it, who's stealing whose work here (if you call that a 'work')?
Anyone would've implemented it without knowing that kind of stuff has already been patented, because it's ridiculous to have such obvious gesture patented.