If you have 50% mitigation you currently see warriors doing double damage with Colossus Smash up. Easy math. You think it's too much so that increase should be nerfed by half and be fine.
Unfortunately, Armor is not linear. Ignoring 50% armor will NOT bring you down to 25% less physical damage taken. Read that sentence again.
It will not bring the Warrior from doing 100% more damage to 50% more damage. In fact, it barely reaches 30% more damage.
With Warriors still being so low in PvE it means that damage must be increased across the board regardless of CS. Ask any cloth how they feel about that. You may just wish you learned to get gear and watch for CS instead of crying about it to create a new problem.
I'm not defending CS, I'm simply stating how ignorant the 50% suggestion is, and how it will simply lead to a new OP for Warriors. Some abilities need to be balanced around ignoring armor all the time, more bleed damage etc. Not 50% CS which just punishes cloth.