For me, it's tied to genre and musical style. Certain effects just lend themselves to certain types of playing.
Distortion = metal and technical 'shredders'
Fuzz = Riffs and blues scale
Muffs are fuzzes in my book:
Black Keys
Dinosaur Jr.
Fu Manchu
Mudhoney
Smashing Pumpkins
Sure, you could play Pantera or whatever with a muff, but it's a bit like ordering a cheeseburger at a Mexican restaurant.