I wouldn't say Sony messed up but I dont think Sony expected this to be high demanding. But you can bet Sony will be upping the manufacturing. They've had a few at every store that I know of but not a lot.
My friend and I got one. He got his at a different spot that sold out shortly after, and I got the last one at my store. I've personally enjoyed the new buttons, easy to use, scary to attach cause you think you might break it at first. Highly recommend it for competitive FPS games or if you just want extra buttons to use.