Allow me to explain (please read).

The hardcore player will always be at the head of the pack when it comes to content (as he or she should be). Going into patch 2.4; the hardcore player has cleared the second coil, likely has a nexus, and has a head start going into the final coil. Nerfs to older content don't impact the hardcore player much because the hardcore player has earned the right to be the first to experience the new hardcore content.

The intermediate player does not have the time the hardcore player has to play but has enough time / skill to take on the "intermediate challenges." In 2.2 and 2.3; the only intermediate challenges were the extreme primals. Unfortunately, the extreme primals reward players with items that are no better than what can be earned via casual content. Going into 2.4; the intermediate player has likely bested the extreme primals, bested turn 5 and is working on his or her animus (or potentially has a novus).

The casual player does not have much time to play and "sometimes" is not as skilled as the intermediate or hardcore players. The casual player runs expert (ironic isn't it?) dungeon roulette's, purchases weathered gear and upgrades the weathered gear with sands of time from Tower runs. The casual player is scared off by the atma phase.

Here lies the problem. Going into 2.4; both the casual player and the intermediate player will enter 2.4 with seemingly the same item level. Atmas are now dropping at a laughably easy rate (2 or 3 per hour some are finding). Books are cheaper than ever (500 soldiery). Essentially any grind time made by an intermediate player was for naught.

Why be an intermediate player? You see no benefit. Grinds are only fun when you feel that you are working towards something but when the countless hours you spend are given away to casuals for free - it makes the grind not worthwhile. I have nothing against casual players. Some of the casual players are the best you will ever meet. The problem is that there is no incentive to play this game at an "average / intermediate" rate. You might as well play as a casual if you don't have the time to be a hardcore player.

Casual or hardcore. No middle ground.