They are not a blurry 24 FPS mess. They are an efficient 24 FPS sweet spot
Today there are no technical problems or impracticalities with high frame rates, and modern cinematography is hitting the limits of what you can do with 24 fps (and sometimes crossing them). 24 fps has become a local maximum because that's what we've done for decades, but it is also a blurry mess.
Furthermore, much of home entertainment is streamed these days. I imagine introducing 60 fps on top of 4k would increase bandwidth requirements beyond what many consumers have access to. It may also be more than Netflix et al want to pay for, so one imagines they'll want to tack on a surcharge as they did for UHD.
Yes, more frames means more data, but it creates fewer problems than the 4k/UHD upgrade everyone willingly goes through, while doing more to increase fidelity.
I looked for 1080p screens when I last bought a TV and couldn't find any. 65", and wanting fairly quality, but no 4k sources so why do I need 4x the pixels? (Sadly, the week after I bought what I bought, I happened across some 65" new in box Plasma TVs at auction... Oh well)
There's nothing new that has to be changed to support this, most of the content people are watching is already HFR.
It's only the narrative based shows that try to be "cinematic" which are at those low fps rates.
But the technology is there, it works just fine.
24fps is far too low.
However if you pause the action, you can clearly see where the rendering shortcuts have been made (The Transformers movies are a good example of this).
It's just as choppy as 24Hz at 1/1600 shutter, but in traditional film, it's choppy and blurry due to the slow shutter, so I can barely see anything.
For quite se time I'd run upscalers to pre process all movies I was watching to 60Hz or 75Hz just because it was noticeably easier to watch.
The argument is that the general populous are used to the 'film look' of 24fps, that anything else diminishes the impact of watching a film. Films that have tried high fps (The Hobbit for example) received negative reviews for picture quality; people just didn't like it.
Also, when increasing the framerate, you should try to stick to a multiple of 24 (i.e. 48, 72, 96) to prevent judder when the shot is panning a scene.
Maybe something's wrong with my mind? But 24/25Hz, even with the correct shutter speed, is noticeably causing strain to process, while e.g. old school TV productions at 50Hz don't have that issue.
And stereoscopic 24fps look twice as bad.
I think you can notice high frame rates. Difference between 60 and 120 fps is striking. Even between 90 and 120. And everyone I was showing my phone that does 60, 90 or 120Hz could see it.
Conversely I don't see much difference between 120 and 240 fps.