SE must be drunk.

[Zojha]

They need to increase the scaling and make monsters hit far stronger with unpredictable damage.

Which would only cause one thing - healers entering cleric stance less often. Mitigation is essential to prevent one-shot protection, but once you can't be one-shot anymore, the healers can pick up the slack far more efficiently than any mitigation stat could. Try running a dungeon once without a tank and once without a healer, you'll see why people rather let a healer do the job than mitigation.