Would you really check random peoples' bazaars even if they were used properly? I mean, that's a whole lot of chance involved that it would be something you want. Out of 40 people on your screen, all 40 might be selling lv15(ish) gear for a fair price that you don't want or need. Or even stacks of Rock Salt, or something. Just as a blunt example. . . . You can't know, since bazaar icons are the same no matter the predominant item category.

I can honestly say I wouldn't bother even in the case of a perfect bazaar scenario. Too much random. Usefulness debatable, except when people sell food/potions/raid drops in obvious places (raid access points).