i'd accept EW's lack of individual merit as a matter of course if heavensward and SHB weren't each prime examples of good standalone, yet continuous storytelling. the story and characters of the respective past expansions were paid off in a way that was well done and could not have happened without the past expansions, yet the core of the story was such that each could have been told as their own, fantastic, standalone FF story. including the pre-expansion storyline as well as the expansion proper, you didn't need to have foreknowledge of the intricate details of the source, the reflections, the calamities, or really even the ascians to fundamentally understand and enjoy the story that shadowbringers told. Stormblood required, to the point of boredom, an in-depth knowledge of the characters, their backstories, their motivations, their personal histories, the countries, the countries' histories, their borders, their individual trade agreements, the garlean empire, and how each of these things react to and change around the others. i could tell you about how the pirates of the ruby sea protected hirogane inadvertently due to their collective hate of the empire and their "protection fees," i could tell you about ala mhigo's relation as a barbarous city state, their relation to the other city states of eorzia, their salt exports due to their great lakes, and much more.
you know what i can't tell you about? i legitimately don't remember why the archbishop thordan chose to go to azyz lla of all places to become the primal king thordan, nor do I remember why they were at war with the ixal. but you know what? it was still a better story than stormblood. i'd much prefer to chase him across the dravanian forelands in order to meet y'shtola's mentor to figure out "when aether shield, build aether spear."
i guess I'll put it this way: with only very minor alterations, one could very easily understand and enjoy the plot of the last harry potter movie or The Lord of the Rings: Return of the King, but i don't see that happening with EW. perhaps the place for this sort of continuous story is in patch content; SHB and HW each had their own .3 storylines heavily building off of the .0 storylines, and SB is basically the same, what with that masterful storyline leading up to the castrum fluminis trial (i forget whatsherface's name). I'm only speculating here, but it may have something to do with the amount of content that has passed since it was relevant, though i personally had a straight shot to EW's story, joining the game effectively just weeks before EW's launch.