What some shielders don't understand, is that they can easily push through the first ranks without getting hit
Definite advantage, for more reasons than you stated. The other day I was on that new underground maze-like map and the enemy team was doing absolutely nothing but camping a single room with a line of melee at the entrance and tons of archers lining a balcony. (It was incredibly lame, and they whined like crazy when half our team decided to turn it around on them and camp our spawn. Of course we lost, because only half our team did it.)
The only round we won was when I said "Fuck this" and pushed through that front line with my shield. I expected to get torn apart on the other side, but what I found was a mostly free route up the stairs to the balcony. I exchanged a couple blows with people on the way, but strangely none of them committed to bringing me down. I made it up the stairs, put away the shield, and took out a couple archers before they all pulled weapons and turned on me. It was just enough relief to allow the rest of my team to pour into the room and emerge victorious from the chaos.
They didn't make that kind of mistake again.
Polearms are unrealistic. The sweet spot on weapons like boulder on a stick should be further away. If I was to work my way in and get close the sweet spot should not hit me. I would simply be blocking the wooden party not the actual boulder therefore it should do less damage and not break through shields and blocks.
I use polearm, and I have lots of trouble with the sweet spot. I get too close quite often and end up glancing.