Currently once all the good maps are played everyone leaves as they are all on cool down and the change to the daily system to per round means there is no incentive for regulars to stick through it anymore, there is also the recent chilling effect on speech that seems to have reduced the amount of players as edgy chat would make even the most boring maps somewhat enjoyable. For new players they could spawn with a main weapon (rifle/mossberg) until they prestige. Also a lot of maps could be made playable by giving survivors decent starting load outs, like on harvest, where otherwise they all die within first few minutes.
We might have to sort out some unplayed maps and reduce the cooldown accordingly. Starting weapons for newbies could be really helpful and would probably have a more direct impact than long term newbie bonus points.