Obviously I am committing an informal fallacy here, but while that may or may not be true across the board, I don't think Return to Ivalice (and as a result Save the Queen) had an inherent entry barrier for people not familiar with it. I have never touched FF Tactics or XII, and I had no problem following and enjoying the story. It was not a masterpiece (though I think between Return and Save the Queen the overall writing got much better), but it was no better or worse or more or less hard to grasp than previous Alliance Raids and exploration zones.
For me personally it came down to the integration with the world. I don't know which plot points are just copied from XII and Tactics, so I don't care that they are, and what I found in both pieces written by Matsuno was very enjoyable to someone like me who loves to dive into the lore of the world. There were no obvious "seams" where I would notice something was copied over in terms of writing, and the game did a decent job of catching me up on all the important information that is relevant for understanding Ivalice in XIV. So as far as this game is concerned, it felt sufficiently self-contained. (Concession though, I did read the Encyclopedia 2 which expanded upon Dalmasca before Save the Queen rolled around, so that might colour my perception of this second half of the story we got)
Which is why I find the unfavourable comparison with CT someone made earlier baffling. CT is merely more relevant to the events of the MSQ, as information about Allag has a much larger influence on the world overall. But Ivalice was no more or less fitting than, let's say Hingashi or Southern Ilsabard at this point, though all play relatively minor roles in the MSQ. But that's fine, it's a side quest and while tying CT so heavily into the main story in Shadowbringers worked out great (and I'm favour of them doing it again), things don't have to be to fit well. I guess it just feels that way to some people cause they don't have to pay attention as much, and if they then decide not to, Matsuno's writing style is pretty incompatible with that.
Also, amen on Dark Apocalypse being a disaster. The direct comparison with Matsuno's work in XIV just makes YoRHa look so much worse, not that it didn't look bad enough to begin with.