Pc gamers say that 30fps is like playing with a pile of shit. Now don't get me wrong, I prefer 60 always, even if I have to sacrifice some effects 60 fps is a must, my rig is good enough but some games are not well optimized so I have to sacrifice stuff :P but I can play a console game at 30 fps just fine too because I'm a console gamer more than a pc gamer. To the point...
On consoles, games that run at 30fps are programmed to run at 30fps. On pc, most of the games or almost every game have unlocked framerate or the option for vertical synchronization, what's vsync? "The basic idea is that synchronizes your FPS with your monitor's refresh rate" the majority of pc gamers have monitors with 60hz refresh rate or higher. That means 60fps or higher.
When your rig is not good enough and your framerates are below 60 or when you try to force and to lock a 60 fps game or a game with unlocked framerate with an external software, when you try to lock those pc games at 30 fps the image is going to look like a stuttering mess because the image is moving 30 frame slower than the refresh rate of your monitor. To avoid that, some games like GTA have an option called half vsync or double vsync. What's half vsync? it synchronizes to half of your refresh rate. So it would cap at 30 fps on 60hz natively and would look better than a game with unlocked framerate locked at 30 fps. Nvidia (adaptive vsync, frame liniter) and amd(amd settings, it's shit tho) also have their own configurations to do this.
Now, I'm not saying this is the only reason, most of pc gamers really can't stand a game running at 30 fps, period. But I'm giving a different point of view, sometimes is not as simple as "30 fps look like shit" sometimes pc gamers have the wrong configuration and sometimes console gamers need to understand that 30fps is not as smooth for everyone like on consoles.
I'm not the best explaining stuff plus my english is very basic so I understand if you don't understand, so here's a video:








