I understand the appeal of this line of argument, and to an extent I agree with it. I think independent invention is a real problem with patents as applied to software. Yet, Samsung didn't independently invent a phone that diverges from the Android default to look more like the iPhone.

Wouldn't it be great to just copy successful devices without paying a designer?

"pinch to zoom" is obvious. It's practically the only way you could zoom things on a touch screen.

It's like patenting the steering wheel.

Don't pretend it's innovative or took any time whatsoever to come up with.

It's blatantly obvious and should never have been granted.

If it's obvious, why didn't it exist on any of the touchscreen products which went before the iPhone?

How many of those touchscreens could detect multiple touches at once? That's a prerequisite for doing pinch-to-zoom with a capacitive touchscreen.

It likely existed on the first light-pen devices from the 80s. Apple just happened to popularize it.