How to make tanking fun.

[TouchandFeel]

Active Mitigation, generally refers to mitigation that is used within a rotation.

It generally doesn't refer to CD's (Though, you can argue semantics that you "Actively" press the CD button for the effect)

I don't believe that to be correct.
While I hate to point to WoW related things in regards to defining things in MMOs, this gives a decent general overview of the idea of active mitigation through the lens of WoW.
https://wow.gamepedia.com/Active_Mitigation

"With Mists of Pandaria the various tanks gained short-cooldown abilities that embody active mitigation. Tanks who use these abilities optimally will be able to overcome challenges that would defeat a less skilled tank."

"The term "Active Mitigation" now refers to a single, specific ability that a Tank must use as a counter to specific Boss abilities. These Boss abilities are designated as Mitigation Checks."

snip

I would posit that debuffs/buffs akin to the old RoH debuff and the damage up buff of Storm's Eye is arguably more passive mitigation than active mitigation since it is just a longer duration buff/debuff that is maintained near indefinitely through regular usage of standard ability rotations.
So I am not sure that labeling such ideas as "needing more active mitigation" is necessarily accurate, however when laid out in actual detail asking for more defensive elements contained within offensive abilities is a valid argument to work from.

I disagree with the integration, or reintegration, of things like the debuff from the old RoH or Delerium combo. They are just there, require minimal thought or interaction and game-playwise add little to how a job plays that couldn't be implemented better in a different way. In the end they effectively not too different than a constant buff like the tank-stance defensive buff. They are just there and are kept up by doing what you would be doing regardless.

On the other hand I am a big proponent of the idea of the interplay between offense and defense in tank game-play and see abilities and ability interactions like the idea of riposte attacks such as is present in Block-->Shield Swipe or the old way in which Reprisal would get it's cooldown reset which was great because it had a three part interplay in which taking advantage of defense with Anticipation would help enable you to make an attack with Reprisal that also provided defense. Another good example is the TBN -> Quietus interaction.

Then if in addition they rolled in choice and risk/reward into these abilities and their interactions I feel that we would be moving in the correct direction.
For example let's look at one of the more reviled tank abilities, Living Dead. What if they added in the effect that when in Walking Dead state the DRK gets a damage up buff? Now you have risk/reward structure of trying to ride out the duration to maximize the buff while risking death or playing it safe and cleansing it early. I'm not saying that they need to do this exact example, just an example of the type of things that could be done to make offense, defense and the interplay of them more interesting on tanks.