His view about games being close to native 4K seems to be over optimistic, but yours is clearly wayyy pessimistic and irrealistic in the opposite sense.
Most PS4 games are already running at 1080p.
And with 2.3 times (at least if they're not upclocking it) the GPU power, 50% added CPU power and extra bandwidth, plus HDR support, improvements will be really noticeable. Sony is sending the message that for them even 1400p would be disappointing and they'd like developers to use smarter solutions.
So expecting 1080p with more stable frame rate as the common scenario is not realistic.
Even the Xbox One S with a 100 Megaflops upgrade can produce better frame rate in a few games

I'm sure they're bringing convincing arguments on September 7th with a few first party games like Horizon and the inevitable Uncharted 4 patch.