This is exactly what I meant. I have been beta testing a lot of MMOs and I really don't mind reporting bugs etc. Also, it is a subjective matter whether or not something is a design flaw. I, for one, absolutely hated the weapon switching system from GW2 - that's why I never bought it. I have played beta, and I would have been reporting bugs and giving feedback just like in any other MMO's beta, but the weapon switching killed it for me. That's just an example.
Obviously, there are also design flaws that are not a subjective matter, but hard facts.