Just to play devil's advocate, I know people who either: A) cannot tell any difference between 30 & 60 FPS or B) just prefer 30FPS.
In other words, it's not a lie they tell themselves - I have no reason whatsoever to doubt them.
I think these people have vision that DID NOT EVOLVE to quickly process subtle differences in motion. I think this sort of general lack of caring about frame rate might also be peculiar to gamers who grew up in during the sixth generation of gaming (Playstation 2, original Xbox, Gamecube), because many of these titles were running at 30FPS.
I grew up on the NES and most of those games (Mario, Ninja Gaiden) were 60FPS. Reference:
https://www.youtube.com/watch?v=jUNzCeesfgw
So whenever we moved into the PS1 era and beyond, where many games were running at 30FPS, I felt jolted, even if I didn't have the technical knowledge back then to explain why everything felt so slow, choppy, and just "wrong."
Then I got into PC gaming. The first game I seriously took online was Quake 2, and, at the time, I was using my dad's Gateway 2000 PC to play, with all its crappy hardware -- and one Christmas I begged for a 3DFX Voodoo 2 graphics card, and my parents got it for me, and after I slapped that baby in, it was like I was a blind man who could see again. My putrid sub 20 framerate skyrocketed to a clean 60-75, and that's the moment that really solidified in my head just how important framerate was. I was getting WRECKED online until I got that graphics card, because turning my camera was so freaking jerky.
So... I think most of the people who dismiss the importance of frame rate are usually console-exclusive gamers who aren't old enough to have played lots of old NES / SNES / Genesis games that ran at native 60FPS.
Try going back and playing FZero or Sonic the Hedgehog, and one of the things that gives those games their incredible sense of fluidity and control is that they run at 60FPS. If you chopped their frame rate in half, they would feel like completely different games and your sense of fluidity and ability to react would be greatly compromised.
Just compare -
30FPS FZero:
https://youtu.be/BIe4AvKLSa4?t=1919
60FPS FZero:
https://youtu.be/i7dusgp9laU?t=10
And this is only visuals. Guaranteed playing the game in 30FPS would
feel significantly worse.
Sidenote: I'm glad someone made this thread as I think a lot of console devs get the impression that console gamers "don't really care about frame rate" and the only way to really demonstrate otherwise is to make noise about it and actively ask for frame rate prioritization.