I can't speak for anyone but myself, but from my own personal perspective it wasn't a matter of "not liking", but rather, outside of Zerith Mortis, the content you listed was resources devoted to content that ultimately was either obligatory (soul ash), or didn't matter past a certain point. A point that fell far short of the point of mattering that the "big three" (raids, m+, pvp) did. Now to be fair, I single out Zerith Mortis because, as a player who prefers to avoid the "big three", I found ZM to be a breath of fresh air, vs. Korthia which was shit IMO.
Korthia was a soul crushing rep AND currency grind to be able to scrape yourself tooth and nail to mediocrity on one character. On the other hand, Zerith Mortis had a fairly decent storyline associated with it (imo) , and the post story repeatable content was generally quick, bite sized, and rewarding. Everything I am looking for. I can't say just how many players look at content like I do, but I know damn well I'm not alone.
Blizzard doesn't know when they actually do shit right. They make changes for the sake of change, or to slow us down because they can't be arsed to make enough content, so they'd rather fuck up what works in an effort to stretch what they do make out longer. Instead of looking for ways to make more content, they look for ways to make less and stretch it out. WoD was shit. It was by far the worst expansion as far as I'm concerned. Legion was a redemption story in my eyes. It wasn't perfect, but it earned back a lot of goodwill from me despite its flaws. I enjoyed Mythic+ in Legion. I enjoyed world quests in Legion. I enjoyed invasions in Legion.
So what did Blizzard do in BfA? They made M+ worse (imo) and it stayed that way in SL. World quests were largely fine in BfA if stingy on rep, but were made worse in SL (gone are the days of kill mr. convenient and shell game wq's for the most part) with the justification that they were less stingy with rep. BfA's assaults were a poor man's version of Legion's invasions (imo). I rarely did them because of the inconvenience and time required factor vs. Legion invasions which had a mix of tedious wq's and quick/convenient wq's. BfA flushed a lot of the goodwill Legion earned down the toilet. And while I consider Shadowlands better than BfA by a small margin (largely due to additional customization, liking the concept of exploring the afterlife, and 9.2's ZM content), it didn't earn as much goodwill and it really needed to in my eyes.
While I only have a bare bit of info on Dragonflight so far, Blizz SEEMS to be heading in a better direction. 9.2 gives me hope that maybe, just maybe it won't be another "you don't need gear if you don't raid/m+/pvp" expansion. That I'm going to have, not just a lot of content to engage with, but content I want to do, that feels worth doing, but isn't a soul crushing slog, and doesn't feel obligatory. No borrowed power + the new talent trees seems like a big step towards the "no obligatory" crap, and interviews seem to indicate they want players to be able to progress while engaging with content they enjoy rather than having no choice but to do things they really don't want to just to improve their character. The "most things account wide other than player power (mainly gear)" is another big plus in my book. I just hope Blizz gives the whole idea of "more challenging content" a break and strives for "more fun content" instead. While some may find challenging content "fun", I do not. I am not interested in being "challenged". I am interested in being "entertained".
I'll be keeping my eyes on news about Dragonflight. I'm hoping that the sales pitch they made in April is more than just flowery words.