There are only three problems with 2h, and two of them are problems with every melee weapon type:
1. The 2h "sweet spot" is too big: someone can start a right swing, and turn into the swing so it makes contact while the weapon is still behind their right shoulder, and it hits for full damage. Compare that to 1h right swing, which will glance during the first ~40% of the swing animation. Side swings from every weapon should only hit for full damage if the target is within about +/-45 degrees directly in front of them.
2. All thrust attacks are more effective when you thrust in the wrong direction then spin into your opponent. This is stupid and unrealistic. In the real world, if you wanted to poke someone with a weapon, you poked straight at them. Doing this in cRPG usually causes you to glance, so people have taught themselves to spinthrust, which looks ridiculous, but is highly effective. 2H just happen to be most able to take advantage of this ridiculous mechanic, because of the huge reach on the 2h thrust. However, it's equally silly with an awlpike or espada.
3. Currently, you can overhead someone, miss, then drag your weapon along the ground until you make contact for full damage. Good players deliberately abuse this mechanic to kill people after they thought it was safe to drop their block. 2h has the longest-duration (and reach) overhead animation, so they are most able to abuse this mechanic, although polearm and 1h can also use this tactic to a lesser extent.
Fix the three issues above, then tone down pole stun, and a lot of the whining about melee mechanics would go away. Then everyone could go back to whining about archers, to which I say just bring a damn shield like everyone else in the history of warfare did.