There is no intention to limit the total number of market items per user, or the rate at which they can put them on the market. It's better to make it possible for people to sell all their stuff without interfering with everyone else's listings.
So if anything, firebolty's way is more effective. Showing one or two items per user. It's not too hard to change the way the list works, though I expect it is made this way for a reason.