Istbor
Dances with Gnolls
Sacrosanct and Istbor, you can keep talking all you like.
Will still not change the basic fact that it is possible to create a character with devastating offense and decent defense.
Not to mention the super-fundamental meta-fact that you can pick your offense, but not your defense. That is, you get to choose who you attack. You don't get to choose who attacks you.
Hence, doing a too-great job on defense will only mean the DM has the monsters attack someone else. (Had there been widespread aggro abilities, then it could have been a thing to make a career out of forcing monsters to attack the unhittable)
A party is never stronger than its weakest member, and there's no use being significantly stronger than the weakest link. Put your energy on offense instead, to end fights earlier.
If you are already decently strong on defense, and get to choose between getting even stronger on defense, and gaining offense, it stands to reason you should choose offense. Only when your defense is no longer sufficient does it pay to shore it up.
This is the minmaxers perspective, the only one to really matter. The perspective that realizes that the only behavior you need to optimize is your DM's.
I don't disagree. I think you can make characters however you want. Glass cannon, balanced, or defensive. I am only differing in how one judges 'powerful character'. I too will sometimes eschew defense and build solely to take down an enemy as quickly as I can. There is nothing wrong in that, and that character is powerful in that regard.
I can't give a definitive answer (opinion) if I do not know how they are hoping to measure power.
You are not correct by stating that only a minmaxer's perspective is the one that matters.