SMGs are close quarters weapons, you don't use them past 100 meters (and even that might be stretching it). And as such, they must be viable enough. Currently, they seem rather lacking - sure, at point blank they are usually the way to go, but even then a simple rifleman can screw your day up any time (1s1k rifles). Point is, since Assault kit puts you pretty much solely into CQ position, you want to be able to perform in that role. You have to be ready for everything that comes around next corner and if you reload 5 seconds, that means you'll most likely bite the dust sooner than you'd imagine. When I empty a whole mag into a couple enemies in a city and I have to reload, as Assault kits come only with a knife (which is useless unless you feel like silently stabbing a camping sniper), I am left defenceless. That kind of sucks for a
CQC class. Much more when it feels like you are reloading slower than you'd be reloading a rifle and there is simply nothing you can do about it.
As for realism: we have to remember one thing, this is a game. You can't implement every real-life like feature into a simplistic gaming world like this. Taking cover in (this) game is not as easy as it sometimes would be in reallife (and vice versa), a stupid box or bigger stone on the ground can ruin your dive for cover and result in death, which is less likely to happen in RL. If we had a vaulting mechanism like in BF3, it would help in a lot of scenarios, where taking cover would become much easier. But we don't and this game is really, I mean really fast paced. Much more than your every day encounter in real life, where you actually might have time to reload, if you're in cover that is, because
no one (apart from suicidal maniacs) will run toward your cover and try to engage you. So you can reload relatively safely. This doesn't exist in game. People will always try and rush you in your cover, hoping for them surprising you. So I wanna be ready for them. If I spend the whole time in cover reloading my weapon, why even take cover in the first place? Give me a bloody pistol then! Oh wait, that goes against history even more
Also I am not suggesting the current reloading speed is cut down to 5% (exaggerating), just a little bit... that sweet spot between BF3's average time for carbines and the current time in FH2. I actually don't mind the fact that the changing of the mags itself takes rather long (although personally I'd make it so that pulling the mag out and putting it back in would be relatively quick, and there would be a longer period of time between the change of the mags themselves), it's the cocking of the bolt that irritates me. It takes forever pulling that goddamn bolt.