Because it is so op, it basically kills armor diversity. On any melee class Resiliance, Shierking fortify is the single best, most op perk combo. And it’s absolutely alternativeless for any serious pvp content.
I suggest to either make pieces with these 2 perks easier available as named items or pvp track rewards or nerf Shierking Fortification altogether.
It’s still a great perk but I would only put it over the aversion perks and shirking heals in terms of perks for damage mitigation. I think resilient is much better. I also had someone complaining recently thinking that I had shirking fortification on my armor when they were trying to kill me. I didn’t, I simply popped Oakflesh balm. Maybe that was you?
I think main problem right now is the survivability in scared grounds. AOE healing is over tuned right now. If that was slightly nerfed then I don’t think you’d be complaining about some players running a bit a shirking fortification and resilient.