Ehh, SP's strength isn't in mitigating tankbusters. Damage reduction isn't additive, and you probably aren't going to save a tank who missed a cooldown with it. It's more about mitigating raid-wide damage.

Also, anticipating for and compensating for mistakes is what tanks and healers do. As a tank or healer, if you hold off on an intervention that could have prevented a death in order to push more personal dps, then you have as much to learn about your role as they do about theirs. We are support classes first. We facilitate raid dps.