And possibly by proximity to the following one, which I continue to insist is the worst of them all (yes, even CoT; virtually nothing of note happens in TPoD, and the two exceptions are an incidental event and the worst one in the series.) The first two times I read ACoS I hated it, but following the third re-read (before KoD, IIRC) it somehow got MUCH better. I now consider it among the best, better than TGH, possibly TDR and possible even TEotW. You forgot Rands fight with Sammael (and reunion with Liah, which deepens already portentious elements in his personality) and titular coronation as king of Illian, btw.

The problem is, the series really peaks at TFoH, and while the volumes immediately before and after it smoothly fit that arc, there is a significant drop between them and TDR/ACoS. It is not that those two books are so bad, but those between are so much BETTER the contrast diminishes them. ACoS has no Rhuidean or siege of Cairhien, no "Choices" or fight with Rahvin (and Moghedien,) no Dumai's Wells or healing of Logain (and raising of Egwene.) It has good stuff, and is a good book, but by comparison with the second quarter it is just... less. For those who read it at the time of release, all that is even more true; after delightedly devouring TSR-LoC when they were new, ACoS could not help disappointing.

Then, of course, immediately after that, the whole series goes to a Hell from which it does not return until at least KoD, if not TGS. Much of that was undoubtedly due to Jordans failing health, but knowing that does not make the reading any more pleasant (if anything, just the opposite.) ACoS is where TWoT ceases to be epic; afterward it becomes mind-numbingly banal and tedious. What crossing the Ephel Duath was to TLotR, ACoS is to TWoT (which I guess makes Fain and the Bubble of Evil Shelob. )

So ACoS suffers the twin burdens of being inferior to the books preceding it and associated with the awful books succeeding it, making it difficult to appreciate in their context. In fact, unless mistaken, I believe the third time I read it (when I finally began to enjoy it) was on its own, rather than in conjunction with re-reading the others, and that may have made all the difference, because I did not have recent reacquaintance with any of the rest to color my perception of it.

It is a good book, but not necessarily easy to appreciate, due to all the baggage.