How is anyone bothered by 13 shield skill players? They're harmless and contribute little to their team. They also die in like one hit.
One on one they aren't much of a problem, you can just as well ignore them.
However, people value k/d the most and everyone wants to get a kill, no matter how cheap it is. That leads to zombie like behavior where 10 people gank one harmless dude which means that somewhere else on the battlefield their teammates are heavily outnumbered.
People who play proper builds usually contribute to their team in a different way (they fight like trained soldiers), while people who play joke builds are also useful but as decoys. That's cool and I like the fact it's possible in cRPG but I look at this as medieval army simulator and would like to see proper battles. The less joke builds and naked trolls running around, the better and more immersive this game will become.