What was wrong with the P-mount ?

So, as some of you may gather, I know very little about turntables. I mean, I know the general physics, the RIAA curve, cartridge loading, stuff any one can pick up from a book.

Sometimes I think of getting into vinyl, especially with a store right across the street, the new Techniques turntables as well as old and new Luxmans or Yamahas, and then I remember the cartridges and all the issues of setting them up correctly, cleaning the vinyl, carefully holding the LP and I return to my digital only lifestyle.

One thing I was thinking about in all of this was, what happened ot the whole P-mount industry? Perfectly reasonable idea to me. Fixed dimensions for the cartridge, adjust the tracking force, and bam, done.

What went wrong?
chak, This or that will work for some P-mounts, but aren't the Technics P-mounts "special", like B&O P-mounts?  Be sure of compatibility.
It’s my first P-Mount @lewm
Looking at the catalog i think Technics P-mount 205 mk4 is standard ?
B&O looks different
I've only had one P-Mount Turntable/Arm — Technics SL-15. It took every P-Mount cartridge I tried, from Technics to ADC, Ortofon, Shure, Audio-Technica. As I understand it, the whole concept behind P-Mount was standardization and ease of use — any P-arm could take any P-cart on a plug-and-play basis — so the idea there'd be differences that rendered them incompatible makes little sense.

B&O did not make P-Mounts. Their own design of "plug-in" is not compatible with either standard or P-arms... which is unfortunate as B&O made some wonderful carts. Moreover, their plug-in designs kept changing, and their cartridges must be matched to the correct model TT/arm.
I can not comprehend, fathom, or understand why any serious audiophile would engage the use of a P-mount cartridge in a Music Reproduction System it is just a compromise offering no improvement, benefit, or advantage.
Technically, I suppose you are correct, bimasta. The term Pmount  probably should be reserved for that one kind of mount. The B&o mounts are different as I already said and you’ve reiterated. Fair enough.