tanks not using cooldowns?

[Whiteroom]

No, it's typically because "Sorry, I was in cleric stance."

Or literally not a single heal being cast because the healer is trying to win the DPS meters.

Your job as a healer is to keep everyone's HP high enough that they're not going to die. When your tank dies because you were DPSing, you're filling the wrong role, period. End of story.

In 4 mans, using vengeance at 98% HP while I'm getting healed and using vengeance at 10% HP while the healer is casting stone are WORLDS different. If you can't see why, you're a bad tank. Keeping cooldowns up with my usual healer, though, is different. Parry cooldowns can also stack with avoidance. At 10% HP, any self heals are WAY more important than they are at 90%.

Cooldowns aren't something you use "just because" they're for survival with bad healers, not so bad healers can win on dps.

If you die while not using cooldowns, maybe it is you who are filling the wrong role.

They aren't for survival with "bad healers", they are what separates a meh tank from a good tank. You're way of thinking here is probably what gets you into trouble. Without using cooldowns properly, you can never be more than a mediocre dungeon tank.

Also it is not the healers job to keep everyone at high hp, it is everyone's job. As a tank you use cooldowns, dodge, keep aggro, and do the mechanics to assist with this.