There are some good back and forth reasons while some are just saying "I want an AH because I'm lazy." The same people are probably the ones saying how "hardcore"(mostly by adding time sink ideas) the game needs to be...
If they add price history to either feature(Ah or MW) than RMT will control the economy again just like XI... Which hurts most and helps few. Even crafters will complain when their item prices plummet. Then the adventurers will complain about item prices when they reach the sun(once RMT gets a full grip).
I hated this about XI but maybe I'm the only one that knew how RMT used the price history to their advantage. Who do you think started the disaster with NM farming for gil in XI? It wasn't players that said "Hmm instead of 300m gil I'll just take 1M for this 30 hr spawn(which was luck I still got the item)."
Also SE didn't ban as many RMT as some might think. They just adapted, grew smarter, and did things under the radar. They also were less bold about going all anon(with stupid names) and making an alliance killing everything.
Also if they add an AH completely what to do with retainers?
Just delete everyones retainer? Then I guess people will want a Mog House? People will complain about those load times too.