Divinepanda 3 things firstly i never said the very start of vanilla you could tank i just said that in vanilla toward the end bears/pallys were used as Offtanks usually overgeared for the content they were tanking the gear was there just low drop rates
second crit immune didn't come in till atleast late in bc more likely in WoLK not sure of the exact timing because i skipped portions but still in normal current content now even with the prospect of getting crit nothing will 1 shot on crit if you have a tank healthpool solong as you are keeping on top of debuffs. you also seem to misunderstand how damage reduction work when compared to avoidance
Tanking while outgeared/outleveling content does not mean that a spec is viable. We had rogues tanking bosses in MC while we were in BWL back in classic, it doesn't mean that rogues were viable tanks, it just meant that we had passed the threshold where mechanics of those fights actually mattered all that much.
Second, crit immunity was in the game pre-WotLK. It was granted by the defense stat, and was the reason that tanks other than warriors weren't viable as raid tanks back pre-BC.
As for whether or not passive tanking, in the context that I'm trying to describe but am probably failing at getting across, I'm not sure. Passive damage reduction doesn't necessarily need to lead to a boring "I'm just going to stand here and let someone wail on me" tank that could be effectively played by one of those drinking bird desktop things. I'm not sure if stacking an avoidance stat would be appropriate for the class, and might make it even more complicated and increase the time to implement this. Perhaps a more take X% less damage across the board from a passive damage reduction, but then healing or shielding yourself to prevent spike damage or to recover the damage from large abilities. Having to think "should I save fury for a shield in 10 seconds, or do I need to use it for this threat ability" etc. Just because our mechanic could be straight damage reduction instead of avoidance, doesn't mean it has to be "boring." Or at least no more so than a druid stacking dodge, or a DK stacking parry, etc. and having cooldowns/resource dumps to up those particular stats.
And I stand corrected on the fury ward SP scaling. I never really noticed it and had to log in game to check that out. /stupid moment.
@Kruil: Phrases like "Not to sound (socially unacceptable term) but, (socially unacceptable statement)." are so obnoxious. How much raid experience does it actually take to validate one's opinion on the game, might I ask? Must I be 16/16 heroic for this current tier to actually have an opinion on a class I love and have played for ~7 years?