This question is mainly about pre-2000 TV series created for CRT TVs, but a lot of it still applies for HD-TV content.
So TVs have been 60Hz/59.94Hz(NTSC) ever since their inception and an old video camera would shoot 60fps interlaced to match the refresh rate. However due to the low visual quality of video, most higher budget series were shot on film at 24fps and converted via 3:2 pulldown to match the 60Hz. Examples would be StarTrek or X-Files.
I can understand why they choose to not shoot film at the full 60fps, as that would require twice the amount of film stock and more light. However what I don't understand is why they went with 24fps instead of going for 30fps.
A 30fps framerate that can be displayed accurately on 60Hz TV seems to be the more obvious choice than going with 24fps and doing 3:2 pulldown that introduces unnecessary judder.
But as far as I know, no TV series was actually shoot at 30fps. Cheap soap operas went for video and 60fps, while all the ones that went to film used 24fps. Only recently with the rise of digital cameras, Youtube and Internet streaming there is now a substantial amount of 30fps content available, though most/all(?) of the big budget productions still seem to go for 24fps.
Why choose 24fps when the content is never going to be displayed in a cinema and most TVs still don't support native 24fps playback? Has there been any 30fps content on TV prior to the introduction of digital cameras and HD-TVs?