Apple did not steal from Xerox. They licensed the good parts legitimately and made substantive improvements. Xerox's stuff didn't draw overlapping windows properly, for instance; redrawing to an occluded window surface was a problem for them and in order to redraw they basically had to redraw the entire window stack. Apple's menu bar (at the top of the screen, where menu bars belong) was a huge usability win over the context menus Xerox employed, enabling -- among other things -- the UI to be manipulated with a mouse with a single button. And on and on.
Look, Apple defines entire classes of devices. That's what they do. Look at the history of PCs, media players, and smartphones: everything that came before Apple's entry into the market was a rough prototype, and everything that came after was a knockoff. Their IP claims are not overly broad for a company whose work shapes the entire industry.