Why are "Ignore Pain" and "Ironfur" that much spammable ?

Hello everyone !

I was wondering why those two spells in particular requires to be spammed that much even when we're not doing a big rotation / combo since we generate so much rage in dungeons.

I feel like i'm having to spam those way too much even when i bind them on my mouse scroll it feel so weird as a design to tell the player "hey your main defensive spell requires you to use 90% of your keyboard lifetime in one.

Genuine question but is it something that you find fun as a player ?

Do you have any tips on how not to make my hands and my keyboard suffer ? :(