The progression data don't support this conclusion.
What's your concept of an appropriately tuned raid, in a world with three difficulty settings? I'm curious, because you've been posting here for years arguing that everything is overtuned.
Do you not like the LFR for randoms, normal modes for organised guilds, heroics for guilds who want a challenge model? Or do you not think they live up to it?
Not the addressed party here, but:
Hard enough to be challenging and feel rewarding, but easy enough to where the lower difficulty setting doesn't surpass you in content.
Personally I don't mind the current difficulty of T15 normal. In fact, I love it. I want there to be difficult, rewarding Normal modes. I have little interest in heroics so I'm happy to have a difficulty setting that's tuned for me to clear (and farm without getting too bored) in the timeframe of the patch cycle.
I also don't mind LFR as a concept. Casuals should have a chance to see the main PvE content in the game, and I think LFR is a great thing in that regard.
My issue is the pacing set by LFR. My primary reward, and motivator, is the content itself. Loot is always going to be proportionally rewarding to its respective difficulty setting (i.e. heroic gear is no more rewarding to heroic raiders than normal gear is to normal raiders). We don't get meta mounts, exclusive content, nor a title (this time), so the content itself is the only truly reward. A reward that is deftly swept away by LFR. Even if I personally choose to ignore LFR (and I do), I cannot stop my guildies from doing the same, and we lose that sense of accomplishing something big together. I feel that LFR gets the same "true reward" as Normals, but at a fraction of the effort. Not only that, but it immediately cheapens (arguably removes) said reward for Normals.
The current pacing of LFR makes me feel rushed and frustrated at the current progression, which I wouldn't feel at all had LFR not been introduced. I don't mind clearing a boss a week on normal. I do mind LFR "clearing" 3 bosses a week and beating me to the punch. At this point I begin to doubt if Normals will even get see to see Lei Shen on Normal mode before he's unlocked on LFR, even with the current schedule.
I don't think it's unfair to ask LFR players to wait longer for unlocks. Heroic guilds get to see content sooner than Normals because they put in the time and effort. Similarly, Normals ought to get to see content sooner than LFR for the same reasons.