If they don't think it's a problem why do they keep nerfing items when a new tier releases? Gul'dan trinket getting nerfed. Tier bonuses getting nerfed. They said several times that they don't like old content items to remain bis. But of course they keep going for band-aid fixes (manually nerfing each item) instead of going for the one move which will fix the problem permanently, cap titanforging on the above tier/difficulty ilvl.
As for your wet wish to remove mythic raiding, part of me hopes it happens one day because maybe then people like you would realise what a sorry state the game would be in.