From what I recall, MoP was the most disliked reveal trailer on their youtube channel because of Pandaren.
https://youtube.com/watch?v=nyeZ8khSEC0
I see that youtube hid the dislikes now but I rechecked last week and it had close up to 36k dislikes (!).
Not to mention that the new expansion barely brought in any new players or older players that quit during Cataclysm.
https://imgur.com/a/5FGbBOY
You can see the dropout after the first few months was huge and t continued to drop down until the release of WoD which spiked up the subscriber numbers immensively. (Don't forget Warcraft movie came out at the same time).
Can we conclude that MoP wasn't that liked by the playerbase? Sure it was good compared to BfA and Shadowlands, but does it show that people are more interested in the "conservative" style of Warcraft; Orcs and Humans too?