Personally, I absolutely loathe the emphasis on battle rifles in a lot of the new games, it's just not fun in the slightest for me - and yes this is entirely because I can't use the BR anywhere near as effectively as I can the smg, but the smg has been made practically irrelevant in some of these games. Of course it's still possible to kill people with the smg who are using a BR, but it's heavily weighted towards the BR on most maps - especially as everyone now has a BR, unlike maybe one or two people who actually prefer using them. This is sour grapes perhaps, but when you've spent a heck of a lot of time using the smg only for that to count for next to nothing in a lot of the maps, it's pretty disappointing.
It's only a game of course, I guess I'll just adapt to the new rules or find something better to play.