If you look at server stats there are between 200 and 400 players online at a given time, now, to be frank, that's pathetic!
Even though there is plenty wrong with this game, to many to list and if I tried I would end up ranting, tho I will list one annoyance, the game is packed to the rafters with weapons for trolls, inevitably some rounds are just full of these people bunny hoping around with a shotgun or some overkill alien weapon blasting randomly around with 0 skill and everyone drops dead.
Of course they think that's fun. but for the rest it just makes you want to give up the round as lost and quit as soon as possible.
But aside from that, when your not being annoyed by trolls, this game is at times a lot of fun, which is why I still play it.
Its a concern that so few play it, I can see all servers being completely empty by the time BF4 gets here, and that's a shame, to see this game die in MP form so soon.