Totally agree. It's not just SMGs, it's just the people who just randomly sprint around and that's all they do. I have been seeing a lot of it recently. If I have to worry about people constantly coming from both sides that really have no tactics or strategy at all the game isn't nearly as fun for me. I honestly think this game would be mpre fun for me if there were no fully automatic weapons.
That probably sounds silly. I mostly have fun with this game, but I usually just leave matches where 4 or more people on the other team are using smgs. I could counter it by straight up camping, but that's no fun either.
Honestly though, I think decreasing movement speed for light weapons would be the best fix.