Why is it such a big deal then, if you're able to become overpowered? Personally, I kinda think that if I want to make my character ridiculously strong, that's my choice, and it affects no one else. So why all this "we can't be overpowered!! Hurr durr!" are the npc's going to get mad? I don't think so.
I understand the idea of balance within player choices: a Mage player shouldn't be able to kill 100000x times easier than a warrior player. However, I think it might be fun if whatever kind of character you choose, you have the option of becoming a god-like monster.
Discuss. I'm interested to hear why people are so anti-overpower.