They place things on a high tier in the beginning and then slowly lower the scale so it becomes more and more accessible to the masses. I would note that it seems like they lower the bar much faster than they used to though.

As a multiboxer who doesn't raid anymore like I used to I definitely feel the same way about wanting a progressive story mode that group sized instead of requiring a raid. Looks like the only way to enjoy that content for the new expansion to come out so you can clear through it.