They may have made billions, but that's not to say how there is a decline of players. Gameplay is getting too repetitive, seriously, the way CoD is going its like the equivilant of making FFXI, FFXI-2, FFXI-3, FFXI-2 Part 2, etc. I cant imagine playing the same game that many times.

Same with Halo, just with more weapons. MMORPGs that are WoW remakes, games these days are just too dull. FFXIV brought something new, but people complained about it and now we are back to using FFXI battle system. My point being that it doesn't hurt to try. I bet if we had AA from the start, people would have complained and want a new battle system.