I disagree. I hate being killed by people who knows how to use a shotgun properly, but the gun is awful already, it's not buffed and it's supposed to be very effective in close range. But still, I can kill shotgunners, before getting in range, with a sidearm (wich I prefer as secondary weapon in pvp) most of times. Just train with your preferable secondary (even fast charging fusion rifles are effective against shotguns) and you'll be ok.