Whenever this phenomena crops up in a game, the likes of Digital Foundry talk about it as though it almost makes the game unplayable, but personally, even after I'm told it's there, I just can't see it. 30fps with "bad frame pacing" just looks like regular 30fps to me. I see no "judder" or "stutter" at all.

Am I mad or does anyone else feel the same way?

Depends. I have seen some extremely bad frame pacing (Halo: Reach at one point on the Xbox One via backwards compatible) which made the game feel sluggish and unresponsive.

And then you had terrible frame pacing on AMD GPU's a few years back on PC, which meant there was a ton of stuttering in games which stuck out like a sore thumb, compounded when running multiple GPU's.

How much this impacts an individual will of course be up to the individual themselves, some people will notice it allot more than others.
Heck, I know people who are okay gaming at 20fps... And I can't stand anything less than 60fps.

Yeah, it doesn't matter how many times I ask what it is or how many times people tell me what to look for, I still can't see it. One day though, I'm sure if I try hard enough and educate myself more deeply on such matters, I too will be able to dislike games based on it. People also talk about games in 30fps being 'unplayable' or 'like slide shows' and, again, I'm yet to discover this new avenue of negativity. I guess I'll just have to miss out and suffer enjoying my hobby. It's my loss.

I see it in Sekiro on my PS4 Pro. 30 fps looks fine to me. Jumping back and forth between 30 and 45 fps on the other hand looks off. I mostly notice it when I rotate the camera too quickly, and the far off scenery kind of stutters.

Maybe you don't notice it because every game you've ever played has bad frame pacing? 

I can see it. It makes the game look pretty much as it was running in the mid-20s even if it's nominally hitting its 30FPS target.

It is super easily noticed for me when playing Bloodborne, FF15 and most of other games which were complained on bad frame pacing especially on base consoles, it is just stuttering and makes very bad experience to me, I really hate that issue.

I notice in some cases but rarely is relevant to me, don't remember a case it broke a game to me.

Yeah, I can't see it. It's absolutely insane how much this is blown out of proportion.

Persons are differently affected by this. I personally am not so sensitive to stuff like that, but I am also not very precise in timing and stuff and prefer usually slower games, so it matches. People that are used to making split-second decisions in games notice it, if these are not working correctly or the image stutters.