I don't think there's a problem with the SMGs on their own; I think the recoil and stuff is acceptable for a limited class weapon. But I think that's kind of the problem, they aren't really limited, especially in lower player games. I run into far more SMGs and semi autos than I do bolt actions.
If you think about like a 32 player server, with what, 5 assault classes, 4 elite riflemen classes, two squad leader classes, and a commander class, that's maybe 10 or so people on a team of 16 that have those weapons. Add the two machine gunner slots and that's even less people with bolt actions. Very few people are actually forced to use the bolt actions because there are so many classes that let you use other weapons.
That makes it kind of hard for people who opt to use bolt actions out of choice when everyone you face has a gun far more suited for close range than you do, or a semi auto that's, quite frankly, better in every way than your bolt action.
While I'm not saying that an encounter like that is unfair somehow in any way, it's a problem that SMGs and semi auto rifles are so common compared to bolt actions when it really should be the other way around. I should be running into an SMG guy every three or four riflemen, not a riflemen for every three SMG guys. Makes it kind of frustrating for riflemen when there are so many people with, more or less, BETTER guns than them, instead of being more or less even fights punctuated by encounters with weapons that outclass you. Unless it's just me seeing it like this, of course.