Digital Foundry also confirm that the graphic setting is on par with PC on High setting is a high improvement compared to BF4 with medium setting

Nice people seem to forget that there is more to graphics than resolution. The PS4 and Xone could handle almost every game at 1080p/60 fps if you tufn AA, lightning, polygon count down. Which have a way bigger impact than 900p instead of 1080p.

Quite true. I'm sure if they removed lots of features from Driveclub it could run at 60fps.

You don't have to be sure, that is a given. Every game this gen could be 1080/60 but the cuts would be too obvious.

Like Naughty Dog with Uncharted 4's multiplayer, I believe DICE made the right call here by selecting 900p on PS4 in order to attain 60fps.

Not everything needs to be 1080p, and as always I commend a developer who priotizes performance.