Using patents as a proxy for innovation seems to be questionable. Most of the larger tech firms develop what are known as "defensive patents". Many of these patents may or may not actually be used for anything, and their actual value is questionable. Engineers will brainstorm an idea, and throw it over the wall to legal, who then will 'refine' the idea into something patentable. Typically, the original idea will only be vaguely recognizable after the lawyers get through with it.
To my knowledge, these patents provide no value to the company or society beyond being a negotiating tool if another company tries to sue them for infringing a patent.
That is to say, the only use these patents have are for big companies, so it's unsurprising that big companies, concentrated in a few metro areas, are the only ones wasting time to create them.