You can't speak for everyone in regards to what "actual real problems" are. For me, this is a huge annoyance, and it is for others.
With my DualShock 3, I'd play for hours in a day, put it away, come back to it later, and play again for hours. I didn't have to continually babysit it and hope it had enough power to last a full gaming session. With my off/on playing of the PS3, I think I recharged my main controller once a month, maybe twice. I realize that part of it is the nature of having a brand new console and using it a lot in the excitement, but I've had to constantly think about plugging my DS4 in and making sure it's recharging.
Maybe that's not a big deal to you. It's a big deal to me. Also, the argument about "buy a long USB cord" are kind of ridiculous. I'm thankful we're now past the era of controllers having cords, and I don't want to have my DS4 continually tethered. I do have a long USB cord, which I use for my DS3, but I'd break it out when the controller was getting low, play using it for a couple of hours, and then put it back away again for weeks.