I don't have the same opinion as them, and, maybe some MMO are not for them, but regarding FFXIV, 2-4 hours daily give you more than enough time to burn through every PvE content, even if you're doing Savage.
Frankly, I doubt so, and, in fact, I've never stated otherwise...the thing is, without gear, any other content would also die in less than a month, except maybe PvP with its season system.
Not, it's not. Yoshi-P is completely free of putting ressources where he wants. Doing Eureka was important for him (He was thinking about it as early as 2.0), so he gave it the ressources. Besides, 18 months of timespan is not 18 months of full time development, and it didn't prevent any patch from being spot on on its schedule. And the participation numbers (However accurate they may be) give him satsifaction. I'm pretty sure in your work too, situations happen where you spend far more time than you should be on something unimportant, just because you want it a specific way. There could be a problem if everything else was heavily butchered as a counterpart, but losing 3 dungeons is really not that big of a deal, since people will simply do their roulette after the first time, and don't really care in what specific dungeon they will end.
Let's dive into supposition, now, shall we. Imagine that in ShadowBringers, they create a whole new content aside the Eureka-type one. This one would be cattered to casual players (according to your definiion). What reward structure do you think this new content should use, that wouldn't make any existing type of rewards irrelevant ?