I often play with just pistols or just a knife. People see me doing it and say, "We should play pistols(or knives) only." Then others say, "No way, that sucks." Then the pistol/knife promoters say to me, "Don't you think we should play pistols/knives only?" Then I say, "That's just how I'm playing, everyone else can play however they want to." Sometimes more people start to use pistols/knives, sometimes they don't. I don't care either way because the pistols are very effective weapons and I have used them to take down hostiles carrying all different kinds of weapons. When I play pistols or knives only I do it for fun, and I don't ask people who don't want to play that way to do so.
I just try to lead by example. Play well, play nice, and respect the other players.