In point of fact, those getting all bent out of shape about this are not listening to views other than their own or considering things from a different perspective. I absolutely come at this as a neutral observer, and I think the developers do ,too. I was not involved in the incident that apparently sparked it, nor do I use the trash cans in this way to sort loot. If someone put something in the trash, I picked it up, and she said she wasn't done with it and wanted it back, I would give it back. If, however, I put something in the trash, another player grabbed it and said "Finders keepers, losers weepers," I also would think that it was my mistake.
Comparing this to pickpocketing is just simply not a fair comparison. These are items your PC only recently acquired--most likely either by killing those who had them in the past, or ninja looting them. Your PC is about to sell them for a pittance. So you've possessed them most likely what? An hour at the outside?
Something *on your person* ICly would be a clearly criminal act. It might be a treasured nonesuch or even an enchanted item that had part of your soul. It could be something you spent hours making. To steal it, someone invaded your personal space.
In contrast, ICly this is a trash can for disposing of unwanted items. The comparison to a crafted barrel is likewise false. If you want a fair comparison, consider if you were a merchant in the Western Outskirts with a crate you had made, and someone came up and started dumping her loot in your crate without asking. That's effectively what you are doing to the NPC merchant--if you claim this barrel is anything *but* a trash can.