I've played some action games in the teens and was fine with it. Maybe lower frame rate at low resolution (1080) isn't as apparent as the high 4K, but I've never understood why people can't play with frame rates still far faster than film (if it's truly refreshing the frames completely and not ripping the picture of course). I suppose this argument goes the same direction as the vinyl/CD one, with both opinions dead sure they're right.
If the game is handling variations of frame rates during play badly, that's a different story. The goal is for the player to not realize there's a change and stay focused on the game.