Aside from Ifrit and Chimera, I haven't seen much fights where stun is that critical. Am I missing something?
I beat Ifrit in a 2 War party and it was really fun. Requires a lot of coordination and there's high risk of being out of sync if someone missed but I had a lot of fun doing it this way.

Plus on Ifrit, the eruptions are really predictable so you know when to go all out and when to slow down a bit on combos and get ready for Stun.
I personally really enjoy to interrupt skills, gives me the impression that I'm really in control of the fight and that I'm supporting my group big time.

That's why I'm complaining so much about the Titan fight, there's nothing for us tanks to do aside from standing in one place and being a meat shield. In Ifrit, we are key for interrupting eruptions. In Garuda, we are key for proper positioning and movement of the overall party. In titan, there isn't much we can do to contribute to the success of the fight.