Trolls usually appear when a discussion involves Enclave or story/cannon. I get the impression a group of FO1 & 2 fans like to routinely bash FO3, I think it's becasue they can't cope with an RPG being a shooter at the same time and they are hopeless without a turn based thing to slow the game down for them
but this doesn't take into account the growing number of FallOut New Vegas fans who seem to be bashing FO3 lately at least they do it on the Vegas section and not here.