Put simply, time is money. If I could make 200k gil elsewhere, those 35 hours I collectively spent could've been converted to 7 mil. Great for the items that can be bought, but for those that can't be, gil does no good. You also need to consider that a lot of these locations are simply "out of the way" from normal play, thus the main reason people go to them is largely for these items. Even if it is something that can be sold, these people are unlikely to want to farm multiples if it took them hours upon hours for their first. I made the comparison to low-drop NMs earlier because they were at least a better chance at getting what you were after instead of killing a mob, hoping for a brown chest, hoping you get good enough clues to unlock it, and then hope the item itself is in it... which is a lottery I certainly hadn't won.
There's nothing wrong with wanting the chests themselves to have valuable items in them, or little bonuses on the side. However, that's certainly not achieved with little things like kazham peppers, flint stones, and so on. Things like the odd piece of Errant gear I found in the Oubliette could at least be NPCed for a few k, or AHed for a bit more. Those make at least trying to open the chests worthwhile. Ultimately, I feel like each "trash" drop should have a minimum NPC value relative to the zone that scales the higher the minimum level range of the initial regimes are.
