I can remember once representing the principal architect of the ScriptX language used at Kaleida Labs (a 1992 joint venture between Apple and IBM) and, when going for meetings at Kaleida, constantly being made aware of the role within the company of a team whose sole job was, day in and day out, to scour everything that was being done for patentability. Given such a focus, you can be assured that countless patents were filed from that effort, not so much because they were useful as because this helped build an IP arsenal to use against competitors.
Intel used patents in this way for years to intimidate and harass potential competitors in the desktop platform that it effectively monopolized for years. Apple is doing the same thing now with respect to its platform. What amazes me is not that Apple is being a jerk about this but that so many believed it would be otherwise. While Apple may in many ways be a rebel company (or at least has cultivated its image this way), when it comes to IP protections, it plays strictly by the standard script.
I wouldn't call it the standard script. Most tech companies actually do show restraint and use patents for defensive purposes only. In fact I heard a heart-warming story at lunch today about how one of the top guys at a large well-known software company recently shut down an internal proposal to start using its IP more offensively. This is, however, the standard script for Apple, originator of the long, infamous, ultimately unsuccessful attempt to sue Microsoft for "look and feel" infringements. For a company that stole so much of its own core technology in the early days from Xerox, Apple has never been shy about making overly broad IP ownership claims. Their legal department has historically been one of the most aggressive and overreaching in the industry. I agree with you that it is surprising that so many people are only now seeing Apple in this light.
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.