Well, if no bidding is involved, the semantics are incorrect. Auction Houses without bidding are more correctly called 'stores' (or, in the market wards case, 'bazaars"), and people should be clear in asking for such when arguing for them. I agree that the process of bidding is a longer process than simply buying an item - it's just another option that has been used in RPGs in the past.
Reading between the lines of some of the posts here, I'm gathering that the real issues in regards to the market wards are as follows:
1. There are several menus to navigate through. Problems with the clunky UI make this process as painful as it is in any other part of the game. It's probably not the number of clicks, but the delay between each click. This is relived once you find the retainer you've marked, since you have to again work through somewhat clunky targeting and sidebar menus to browse the retainer's items, and then a clunky purchase interface. These are mostly issues with the UI, and not the MW. The "stay in one place to do all of your shopping" mindset does alleviate some of these issues, but the UI would still make the experience a bit annoying. I believe UI fixes have been investigated and implemented (albeit in small doses) with each patch, so it may just be a matter of time before the bigger issue is tackled.
2. Once a desired item is found in the item search counter, the player must enter a new area to purchase it. This involves an awkward loading time and a transition to the same room that composes each section of the ward. For the bit of travel necessary to fetch the item, and the loading time involved, there is very little flavor or reason for things as they are.
I would like to mention, however, that there still is the issue of the AH in games like WoW, in which purchased items are placed in a Mailbox, and must be retrieved from there. This adds some travel time in the same fashion (and if many items are purchased at once, many items must be retrieved from the mailbox). Again, I think the issue is the slowness of the menus, and the loading time required to render a new room when travelling between market ward locations. They're just small annoyances that add up when executed in succession.