I'm not so sure whether the unnatural part has to do with smoothness.

A bigger difference is lighting. 60fps requires different lighting requirements for film and tv which makes a bigger difference of the final look.
Although different. games also differ in lighting, 60fps, less time for fancy lighting passes per frame. (on console)

Smooth motion on tv looks unnatural as it can't undo the motion blur that was inherent in the 30 fps video. It merely smears that blurry picture out over 60 or 120fps. The movement now looks smooth yet it still has that blurriness of 30 fps video.

Of course it's also part of what you're used to. If your brain has learned to perceive 30fps as natural for all your life, then the occasional 60fps outlier looks weird. If you switch enough between the 2 you probably don't even notice what the fps is after a minute. I don't anyway.

I don't think that's odd at all. The closer in you are to a screen, and the higher that display refresh rate, the more forgiving you can be of lower FPS.

60 fps can always sync properly to 30 fps and will look smooth to the naked eye. The frame times are so small that you get proper frame-to-frame turnover to your eyes regardless whether your not your eye truly sees all frames (it doesn't) However something at 50 fps will likely have uneven frametimes here and there - making stuff look weird.

30 fps conceivably should be smooth as 60 fps, but that assumes your eyes will process the frames in perfect progression/turnover and that frame times are even - neither of which are both the case 100% of the time.

When you sit further away, the image has to travel further, you process the image later and you do feel the difference in how responsive the game feels. With higher FPS, your eyes are more likely to see the frame in sync with gameplay.

More like massively overrated. It makes no differenece at all. You don't play better or worse if a game has 30 or 60 fps because human eyes can anticipate the movements on screen easily. That's biology. The non-swimmer blames his bathers.

I actually had a little bit of trouble telling at first in that video (although I did get it right after a bit). Having it side by side like that was a little disorienting for me. However, I can tell when a video is in 60fps. As for games, EVERYONE can tell the difference. Assuming no screen tearing or drops, the difference between 30fps and 60fps when gaming is immense. You can both see and feel the difference. If anyone says they can't tell, then they just don't know what they are looking for.

Now I'm not saying that every game on every system in every circumstance must be 60fps always, but I am tired of people trying to delegitimatize other people's desires for better framerates in games because they think there is no difference, because that simply is not true.

yes. with the Dark Souls dsfix on pc, you can switch back to 30fps by hitting the backspace button, and the difference is astounding. 60 fps is so much smoother, more responsive, and appropriate. There is a HUGE difference. 

Unbelievable. This post of yours is so patently false that I almost find it fascinating.

1 frame tricks/windows are prevalent in a multitude of competitive games. Even tiny variations of lag (less than 1 frame) between different televisions can affect the outcome of a match if the player isn't used to it, which is one of the reasons why games like Super Smash Bros. Melee always feature handwarmers/button checks at top level. Needless to say, a person playing at 60 fps would have a massive precision advantage over a person playing at 30, regardless if we are talking about shooters, fighters, racers or whatever.

Console gamers...cmon DansGame
OFC you can see the difference.

You can see the differences between 144/120fps over 60fps. Which is why every CSGO pro has a 144Hz monitor. People who play fighting games wants 120+ fps as well.

Its hard to go back from 1440p to 1080p but its far more difficult to go back to 60fps from 120/144 fps.

120fps with Lightboost gets rid of all motion blue current day monitors have that CRT monitors did not have.
But I still prefer 144Hz on a CS:GO, less latency.

when side by side and the guy was sprinting and i looked directly at the ground i could tell.

i find that an absurdly convoluted set of criteria to "notice" the difference and a waste of resources for the game. give me 30 fps and a game with better draw distance, textures, poly count, npc count, resolution or really anything else. anything else is more impactful to the overall experience to me than the framerate increase beyond 30.

When I play mariokart, I can easily tell the difference from when I'm playing alone to when my sister joins me.

30 FPS looks more choppy compared to 60 FPS

There's definitely a difference! When I was a kid I watched Link's animations in Ocarina of Time and wondered why they had chosen to make the game so choppy (OoT runs at 25fps). I hadn't even heard of fps back at that time but I always loved watching my characters move on screen and there was a noticeable difference between games. Some felt a lot smoother than others, but I had no idea back then why that was. It never felt like some games were superior to others to me: I always thought the (lack of) smoothness of animation was a deliberate choice, it was part of a game's universe, part of its "feel", but I could always tell there was some sort of difference between games.

Today, it's crystal clear to me that Mario Kart 8's split screen feels choppy because the game drops to 30fps of course (and it's a crazy difference! It feels like being hit on the head by a brick after playing smooth 60fps in single player), but back then it was just part of a game's magic. So yeah, even back when I had no idea about fps at all I could feel the difference.