Apart from the obvious bias having been written by a co-founder of a product studio, there are plenty of examples of product studios not working out. It's also a hugely saturated market now. Success stories (e.g. UsTwo) are very rare.
My other thought is that, while it's not quite the same thing, if you look at modern movie studios, it starts to look a lot more like VCs than anything else. They hear pitches, they help develop promising ideas, fund pilots in the case of series, and green light a relative handful. So product studios seem more a variant on VCs than anything else.