For certain games resolution does enhance and directly affect the gameplay.
Being able to spot someone from a greater distance makes a difference in FPS games. The extra resolution in racing games gives you a much better feel for the upcoming corners at speed, or the traffic in arcade racing games. In RTS and building games you can get a bigger overview of the action.
Yes gameplay comes first, but extra resolution gives you more of an edge in fast arcade racers then 60fps. Simply cranking up the detail in 720p can also make the game too cluttered/busy/noisy to get a good grasp of the 3D world. The extra resolution restores the balance. Same as you would not do well playing current gen games in 320x200, which was a perfectly fine resolution for Doom, Half-life and Descent back in the day.
Crank up the resolution and maybe one day we can discard with over sized glowing items and enemy markers to make them visible enough in the pixel clutter. (That also depends on better lighting and AA ofcourse so not everything blends together)
Anyway sure, arguing over a 2D platformer in 720/900/1080p is pretty pointless.







