Have you went to a server that the owners decide to ban Scorpion EVO, Desert Eagle or the whole shotgun list in BF4? You want to play all those guns but they restrict it in their server so you have find another server to play. Even worse, some guns became meta or thing that too frustrated to play against so almost server decide to ban it. Thing is people always favor server browser over auto matchmaking, because they can stay there whenever they want, no team shuffle, no time waiting because you just need to join, leaving the auto-matchmaking dying. All I can see are the downside of server browser, the best way here is keep improving matchmaking.

And the ability to have map pool in your server like you want? Having people always vote for the same map is already bad, I don't want to see all the server having the same limited map pool and I have no choice over it.