honestly, i've never been told that i've been doing a build wrong (or a "wrong" build), and i barely know what i'm doing on any melee AT. so i surmise that people like the OP, who just play the game to have fun and only speak up when someone's playstyle affects the performance of the team negatively, are in the majority, and it's part of what i love about the cooperative aspect of the game; people in general are pretty cool about sub-optimal builds, in my experience
either way, i appreciate people who use the OP's mindset