Because content shouldn’t be designed and balanced around people it isn’t for.
You have players that won’t ever really engage with the likes of raiding. Raids shouldn’t be designed and balanced to try and please those players - they should be designed and balanced for the enjoyment of the raiders engaging with the content.
Thus Blizzard are giving those players their own system instead, Delves. A system OP barely engages with, yet made a thread about.