It's not selling *that* well actually and he knows that. This is just marketing. The PS4 is selling way below the PS2 (200k-300k per week), the Wii (300k-400k a week) and the DS (400k-500k a week) and even the PS3 sold better than it after the 2009 redesign. It's not selling bad either but they sure as hell didn't expect it to sell any less. They had problems manufacturing the console at first but that's totally normal for Sony - the PSP and PS3 were delayed in Europe because of the very same reason.
Still looking forward to my white PS4 though