They're not lying to the customers, and the game isn't an exact historical recreation nor, I believe, does it claim to be. You personally may be disappointed that there are more SMGs than rifles, but to me, this simply belies your preference for the rifle. If you weren't a rifle fan, you wouldn't care. Likewise, due to your preference, you see to want others to have to play the same way. Again, if this wasn't the case, you just wouldn't care.
Personally, while I really like the bolt action rifles, I don't see any change in the game, and certainly no change for the worse due to there being more SMGs or semi-autos available. The rambo/COD style players still play the same way and will pretty much always play the same way, even if you stick them with a boltie. That or they'll cower in the corner and plink with said boltie. Don't believe me? Play a round or two of Kaukasus or Basovka with these guys. They're either charging around AS IF they're using an SMG, or they're huddling in the darkest corner they can find, plinking away and not getting into the cap zone.
That's just how some people play and it doesn't matter what weapon you give them. The only impact that giving them an SMG has is that it makes them more effective when they finally do get into range. The trick, then, is to not let them get into effective range, or to simply be a better shot than them.
Another simple fact is that many of the RO official maps (and unofficial ones) are close combat affairs where you'd WANT an SMG handy. All the urban maps are ones where an SMG is the weapon of choice simply because it's the most effective. While most soldiers might've been equipped with a longarm throughout the course of the war, there's nothing to suggest that they couldn't have been issued an SMG for an assault mission like street fighting in an urban environment.
Regardless, to me, the "it ruins historical accuracy" claims are a smokescreen for the "I just like the way you have to play when you use a rifle" claims. Historical accuracy is a lot more flexible, I think, than many people seem to believe, especially when we're talking about aggregate numbers like "Total number of rifles issued vs. total number of SMGs issued" in comparison with specific engagements where you'd really need to know the order of battle for the listed units to raise claims of improper historical accuracy.
By the way, there's nothing really wrong with saying "I just like rifle combat better and wish more people dug it the way I do". I understand that. But (a) I'd advise you to play on those maps where a rifle really is the weapon of choice, and (b) to accept the fact that you can't make people play the way you want 'em to, even when your way is more effective and even when they'd find it more fun if they only gave it a chance. All you can do is encourage them to give it a shot and hope they try it and ignore them when they refuse.