BF3 doesn't appeal to as many people because you know most people don't like to run across a fu*ken map on a video game just to get shot by a sniper camping on top of a rock or in some bushes.
for some1 to have played bf3 you should know it has the best spawning system of the two games. only idiots keep spawning at the starting point and RUN across the map. normal ppl spawn on their squad, objectives, vehicles ect. best of all you can even see where your spawning before hand.
maybe you personally like getting spawn r*ped, or doing it to some1. getting shot in you back because ppl spawn right behind you after you k!ll them, may be thats your thing
and hell naw mw3 has way more leg and terrible match making.