Trust me, I value my time way too much to do anything to my 4R that doesn't bring value or some kind of benefit.
Check the 2nd pic in my original post and you'll see the base of the Skydock that enables me to use and charge my iPhone in the truck. So no room there for a plug-in charger.
I needed a USB port to keep my iPad charged while traveling and to power it during use if necessary. My job involves emergency response and if a call comes in while I'm out in the truck, I have to be able to work off my iPad to execute the checklist we use. To that end, I also carry a portfolio with supplies and a Logitech Keys-to-Go wireless keyboard.
Finally, I also plan to drive my truck into the ground and don't care about resale; but if I did, I can't imagine a buyer thinking a vehicle was less valuable because the owner added USB power ports, especially if some effort is made to get as close to a stock look as possible. I'd bet in fact that the large majority of buyers wouldn't even realize this is a mod.
Probably way more info than anyone cares about but hey, you asked.