TL;DR: AT needs Marm back
AT has seemed determined for a while to make the absolute worst decisions when it comes to the wotlk realm. It has always been AT's only constant when it comes to staying alive. While every other x-pac died fairly quickly, wrath has always been there. At the same time, almost nothing has been done to stimulate the server for a while now. Post-merge, wotlk has been kept entirely in the dark with 0 advertising, 0 promotions, almost 0 admin responses to questions. Everything has been declining for a while now, but the only thing done to change that was to add solo queue, which kind of just killed the 3's ladder. Without 3's, a lot more people are deterred from playing since it's just the same 5-10 god tier players playing lock/mage/ele wiz cleaves.
When AT was in its prime with thousands of players online and top players queuing left and right, they should have started adding all the cool stuff to keep people playing like they did later, once the playerbase was on the decline. It's all about taking advantages of opportunities, and wotlk while the best opportunity AT has ever had has given a lot of leeway, the admin team instead has decided to devote time to opening every single fucking xpac known to man, all of which failed, followed an extremely poorly thought out merge with molten, which hasn't helped for shit and has probably lost AT more money because the donor store was never restored. I understand a little since the team is small and probably overworked often.
Something else to consider about why a lot more people are jumping onto the cata train all of a sudden: it probably has and will benefit WAY more from the merge than wrath ever will. Molten players are awful arena players; they embody what the retail playerbase is more like: the few good players followed by the army of retards. During the first few days of the Wotlk molten merge, a lot of scrubs showed up, but they quit in a few days once they got globalled in a shadowfury/bladestorm by players who have no right to be at 1600 mmr. There seem to be way more molten players interested in playing cata, which means more filthy casuals, which means more donors, which means more money, which means more advertising, which means more casuals, which means more queues, which means more decent players.
we'll see where things end up once the staff announces the wotlk tournament+malaco said they are going to be giving a lot of Wotlk love soon
Wotlk has obvious balance issues, but cata sure as hell does as well. The issue isn't balance, no matter how many LSP/warrior holy paladin posts people make on the forums. The lack of diversity stems from a lack of a diverse playerbase, which only creates a cyclical problem. ON THE BRIGHT SIDE, IF YOU WANT WORLD PVP, ALL PEOPLE SEEM TO DO NOW IS WORLD PVP ON ISLE OF Q!!! Worldpvp-tournament dot com