Theres a difference between having enough hp to endure tankbusters and wearing str accesories, and wearing str accesories with not enough hp. On the first case is only the tank fault if the tank doesnt use cds, on the second case is always the tank fault due to failing at maths.

Lets not talk about extremes, since the idea is survive+ have extra dps. Most of the tanks will say that they play switching vit/str accesories, depending on the fight needs