Why do people care about fps?

Because first person shooters are nice, i love TF2!

Under 60fps doesn't feel right

When there are small FPS variations you notice it more with 30 than 60. A drop of 3FPS is 10% instead of 5%.

You'll notice it immediately, 60 is way smoother.

What's the difference between 5 fps and 30fps?

here's to hoping Blighttown stops giving us headaches. . .and i'm not talking about enemies, environment n general gameplay, but rather the technical side of it or lack thereof.

I used to say there was no difference, then I saw some 60fps stuff and was like "Okay, this is a bit better." I don't think 30 FPS ruins the experience, but 60 FPS can be a lot more satisfying in some games. However, the biggest thing in my book is stability. If a framerate really jumps around it bothers me.

As others have said, though, the type of game matters. For turn based games (unless they have a ton of animation going on) or point and click, you really don't need 60 FPS. For twitch shooters and eye candy games, 60 FPS is rather desirable.

In particular for Dark Souls, the switch from 30 FPS cap to 60 FPS is also significant because Dark Souls (the non-Remastered version) had a 30 FPS lock tied to the physics engine, so things were different if you cracked the FPS limit. Gameplay wasn't hugely affected, but falling damage and some effects were impacted in ways that were rather annoying.

Generally, the refresh rate required to not break immersion (i.e. for video to look like it might be real and not a stuttery mess) is a stable 24 FPS, but 60 is generally the "buttery smooth" number while 30 is the "I want this game to run stable" number. I can't help but feel that some of the antipathy towards 30 FPS is a bit of pretentiousness, but there is a significant difference.

MIT's Media Lab has done studies for decades and found that FPS is more important to immersion than resolution or colour but for decades publishers have focused on the wrong things.

It depends on the game. For games with a lot of action (racing, fps), I think 30 and 60 are both too low. I personally like 85 or more and will take a lower quality if I get more fps in those games. In a slower paced game, I prefer the eye candy and will go for resolution and effects over fps.

You're right, people shouldn't care about fps, they should care about frame times.

Some games benefit from faster frame times, where getting a new frame every 16.6 milliseconds (60 fps) is beneficial over getting a new frame every 33.3 milliseconds (30 fps). The faster frame times lead to better and smother response in fast paced games. 50 ms frame times (20 fps) can make a game feel slow and unresponsive.

But more important is the average and low frame times. A game that has an average frame time of 18 ms, but slowest frame times of 50 ms, will run well most of the time but have moments where it stutters and feels choppy. A game that has an average frame time of 34 ms and a slowest frame time of 35 ms will appear much smoother overall despite the slower average frame time.

Frame times also illustrate the relative benefits of video card performance much better. For example, moving from 33.3 ms to 16.6 ms (30 fps to 60 fps) is a much more significant improvement to the feel of a game than 16.6 ms to 11.1 ms (60 fps to 90 fps). Increasing a game's performance from 45 fps (22.2 ms) to 60 fps (16.6 ms) is as significant as going from 60 fps to 90 fps (16.6 ms to 11.1 ms).

Faster RAM or more video card memory may not effect average fps, but can have a huge effect on the slowest frame times, increasing how smooth the game feels.

Try playing a fast FPS like Quake 3, UT99 or whatever in 30 FPS. Afterwards, try 60. And for good measure, try 120 FPS as well. You'll see the difference immediately.