I think what you are missing is that making something take longer doesn't actually INCREASE content... you are just dragging out the SAME content. How is killing a mob 1 time better/worse than killing a mob 10 times? Did the mob CHANGE between the first time I killed it and the 10th time? I would argue that it did change... for the worse, because it got easier and easier to kill to the point where it just got boring. I don't mind doing something multiple times, but this is why I also have issue with the darklight gearing system. To get a full set of darklight gear I have to complete AK at LEAST 65 times. How in the world does that sound "fun" to you?
Since your Conjurer is only 32, you still do not have a max level character and cannot speak at all toward FATE grinding being "too fast". Why? because you cannot FATE grind to 50 and then call it a day on your first character. YOU HAVE to at least do all the story quests (even if you skip all the side quests) which is going to take time, and force you to run around the world. While you are running to the various zones anyway, you might as well do the side quests since it is actually a faster way to level WHILE completing the story. Being 32, you haven't even hit the worst of it yet, since you will be going on tons and tons more go to this zone, then go to this zone, then backtrack here, backtrack there, backtrack, backtrack everywhere!
And you HAVE to clear through the story to even unlock the HM primals, which you have to do to unlock the raid. So everyone that is "quickly" pushing to the endgame and "clearing content too fast", did all the same story quests you are doing right now, all the mandatory dungeons (there at like 8 of the 11 or so that are mandatory), did the three normal primal fights, and then grinding AK 65 times to get into BCoB. So how are they already doing at this, because it is certainly not a "fast" process. They are playing hours and hours on end, for days and weeks on end.
Bottom line, those who are primarily FATE grinding are leveling their 2nd and 3rd job to max level. That has NO effect on game content, since you only NEED one job to do the content. So all your points about why it should be nerfed are moot, since it comes from the basis of slowing down the leveling process of your FIRST job. Now if you want that to be slower I think I would rather shoot myself in the head... the story quest itself already has you doing tons of pointless stuff just to drag it out as it is... to the point where they are making fun of themselves in the process (the part of the story out at wineport in the 30s comes to mind...)