@NicTheGOAT
I feel exactly the same, I wake up and want to play but aside from levelling classes up solo I'm bored of almost everything. Some classes as you've stated already are painfully slow to level, you're never going to play them ever because they suck so bad, and the time it takes to level them sort of reflects how bad they are, for the most part. You go online to try and have some fun and well, it's not fun to be steamrolled when things are broken. If it was purely based on skill as opposed to balancing issues then fair enough.
You try and vent your frustrations on the forums, and well instead of being salty you try and suggest ways to balance things (I'm extreme because I get to know who is actually playing which side this way), and ultimately you're shot down because the majority of players enjoy playing zombies anyway. Which doesn't really leave the developers in a good position either because if they balance things out, they're going to upset all these skill less players who need the overpowered characters just to win.
I don't see this game ever being balanced, I know a few mods hover around but for the most part they've stayed silent this whole time. I'm stating to get tired of repeating myself and arguing with the same players because they're never going to agree, some are even on the PC and don't understand how different console gameplay is. Everyone should be able to pick any class and variant they want and stand a chance to play well, in any game mode.