Are tanks a scapegoat for performance issues?

[RopeDrink]

Wipe because boss keep hitting Other beside tank? Obviously tank fault
Wipe because dps keep getting hit from avoidable red circle? Dps fault
Wipe because party hp bar keep getting depleted? Healer fault

Problem with this sort of thinking is that it completely excludes the circle effect. For example, let's say DPS is being sub-par (beit experience, gear, rotations, or because a tank sucks at positioning) which makes for longer fights, which pushes healers towards MP concerns, or (in terms of above mentioned dungeons where everything and their mother is doing gross AoE damage every ability) increases the risk of people just flat out dying to mechanics, whether they're failing at dodging or not - and this not being helped by, say, a tank that isn't using mitigations on a rotation thus the Healer has even more to worry about, etc. etc.

In short, it's a group effort, and wipes don't always happen as a result of an obvious 'absolute'.