It is bizarre choice on Tripwire's part.
I *like* the stats system for logging both team points (Honour), class usage and weapon useage, but the choice of actually boosting a player's attributes based on those factors is beyond daft as a design choice.
As pointed out, all it does is penalise new players joining the game by creating an artificial barrier between them and the oldies ontop of the actual players gaming skill.
Personally, while I wouldn't ditch the stats system, the attribute boosts (taken from KF) need to be nuked from orbit, as like others have mentioned, the unlock system needs rejigging completely.
I was actually mulling over the MG unlocks last night. I thought that the best way to have level 25 upgrades for the MG34 would be a loadout choice of either:
A) Extra drums (ie, more ammo capacity overall)
B) Belts (which should reload quicker as you're not faffing around with a drum) but only two of them with one in gun and one spare.
The idea being if you choose A, you are more self sufficient as you're carrying more ammo, but you face frequent reloads and can't perform lengthy surpression fire.
Choose B and you can fire off long bursts, surpress for longer, reload quicker, but are faced with needing to rely on teammates for ammo as you only carry one reload.
That's the type of unlock system that should exist, one with at least a personal choice if not a tactical choice, which really are sidegrades from each other.