It's interesting reading all of the love for WotLK in hindsight, when back at the time it was extremely controversial. So, so many of my friends and guildies lost their love for the game in the WotLK era, with many of them who had been hardcore players since Molten Core quitting our raids to go play LOTRO or Aion or Rift or whatever was the new FOTM MMO coming out (all of which subsequently died, of course, but most of those people never came back to us).
However, Wrath was the beginning of the true age of accessibility in WoW, with an incredible amount of QoL improvements, easy zergable dungeons, casual raiding content and nerfed levelling experience. This, along with the obscene marketing push that Blizzard had going during this expansion, brought in just as many new and fresh players as oldschool Vanilla/TBC players who were leaving. The population on a graph for WotLK looks to be pretty much a straight line... but Wrath has the biggest influx of new players in any expansion, and simultaneously one of the biggest losses of older players, which kept things looking very stable... but in truth, there was a lot of churn for sure.
I'm sure people from that time remember the "Wrathbaby" term. Now the Wrathbabies have grown up, and they're the old fogeys talking about how things were better back in their day
Makes me feel proper old.