Plugging in to your Kindle PowerFast adapter that only fast-charges a Kindle? Plugging in to a PMP that that supports USB-MTP or USB-MSP, which Apple doesn't support at all? Plugging in a HDMI or VGA adapter? Wait... they don't have those for micro-USB. Reusing your PDMI gear? Ooops, those are only pin-compatible with 30-pin and haven't gotten any real traction. Plugging into a USB audio device? Oh wait, THAT STANDARD DOESN'T EXIST EITHER.
So I'm begging you, tell me, my mind is OPEN on this: describe the benefit of Apple moving to micro-USB beyond "I can reuse my BlackBerry charger from 2005".
I can't come up with enough pros for anyone, including the customer.