I wouldn't say that most pickups are MC these days--there are still a fine selection of each, in widely varying price ranges. Clearaudio makes excellent MMs, as do Grado, Dynavector, and a number of others.
On the other hand, I could conjecture that MCs have been gaining in popularity with the wide disappearance of typical MM stages in low-end gear. Vinyl has gotten to be more "high-end" oriented, and in the high-end camp you're much mroe likely to find enthusiasts who own the high gain stages necessary for the low output of fine MC cartridges.
I'll let people with more experience talk about sonic difference, but I will say that in my limited experience, I have heard good MMs sound very similar to MCs...
On the other hand, I could conjecture that MCs have been gaining in popularity with the wide disappearance of typical MM stages in low-end gear. Vinyl has gotten to be more "high-end" oriented, and in the high-end camp you're much mroe likely to find enthusiasts who own the high gain stages necessary for the low output of fine MC cartridges.
I'll let people with more experience talk about sonic difference, but I will say that in my limited experience, I have heard good MMs sound very similar to MCs...