WotLK was the first expansion whose new content did not include any new zones in the Eastern Kingdoms or Kalimdor, the continents that were included in Vanilla WoW. Cataclysm, in contrast, is set almost entirely in the Eastern Kingdoms and Kalimdor.
All raids from Vanilla and Cataclysm are on those continents (or at least have entrances there), and the same can be said for some TBC raids such as Karazhan, Battle for Mt. Hyjal, and Sunwell. NONE of the WotLK raids are in Eastern Kingdoms and Kalimdor though. (Onyxia’s Lair does not count due to being copy-pasted from Vanilla.)
People think that because WotLK wraps up a story from WC3, it’s somehow more of a legitimate part of the “classic era” than Cataclysm, but actually Shadowlands is the expansion that wraps up that story, so they’re wrong about that anyway, plus having a main villain who is at the center of all the events in the expansion actually makes WotLK less like Vanilla WoW compared to Cataclysm.
Also, Cataclysm was the first expansion since like maybe the beginning of TBC where you were likely to see people walking around in gear from Vanilla, because of transmog. In WotLK you mostly only saw gear from WotLK, and it was all brown and BORING, and people hated that so much that maybe that’s why people petitioned for an “appearance tab” (i.e., what people called transmog before transmog became a thing).
Also, compared to WotLK, the number of people who were subscribed to the game by the end of Cataclysm was much closer to the number of people who were subscribed to the game by the end of Vanilla.
Also is it a coincidence that the least liked raid of Cataclysm (Dragon Soul) reuses a lot of WotLK assets? In a way it’s like Dragon Soul was really a WotLK raid in spirit, if you think about it, and that may be why everyone hated it. In contrast, everyone loved Bastion of Twilight, Blackrock Descent, Throne of the Four Winds, and Firelands.
Blizzard needs to know true classic fans want to skip WotLK Classic and go directly to Cataclysm Classic!