We want tools of computing to be as useful and flexible and free (in design) as cement, steel girders, wrenches and sockets, pencils and paper.
While the general concepts of those tools are free and open, there are patents on specific implementations of all of them. People are always inventing better wrenches. If you made a copy of Craftman's new wrench of the week and started selling them, I'm sure you'd be hearing from their lawyers.
We live in a world, wrong or right, were people innovate for profit, not the betterment of society. I don't see why people feel computing devices should be any different.