It's called a contrary opinion with every topic posted. Not to play devil's advocate or spur conversation, but to draw the ire of the forum.
I just noticed I said 900p 60 FPS there, when the OP was suggesting 900p 30 FPS. Which, is a valid suggestion, actually.
Visual quality is definitely a factor. You can get more effects into a game that's 900p 30 FPS, but then there's the issue of smoothness.
Some displays might not seem as fluid in gameplay that's variable between 30-60FPS, as they would if things were locked to 30. On the Xbox One, the visual benefit from going from 900p to 1080p, might not be worth it, since the GPU just isn't large enough, and the memory bandwidth just isn't there, to run things well at that resolution.
It's too bad it's not left up to customer choice. I would really like the option to change settings like this in game.
On the PS4 some games have added some minor graphic control options. I recall being able to turn off some effects like FOV in Warframe, inFamous lets you lock to 30 FPS if you want, and FF14 lets you change between 720p and 1080p resolutions. A game like Halo could be a great trend setter if it had lots of graphic options.