From what i've seen from reports and such. There has been, once again, an uproar of users that get a kick out of going onto servers and hacking to make their puny lives feel better. As such it kills the server. Takes a little while for population in them to fill again.
Yes hackers can kill any server, or maybe bf3 it's starting to die and the time to move to a newer game is coming idk (i hope not).. i say this because not only tbg servers have been rather empty lately, but others who used to be populated are empty too.