I agree (assuming I read it correctly) that we don't bother checking to see if someone needs something. If I am running a Wizard and a Barbarian item drops for me, I just "gift" it automatically (pick it up and then drop it again - making it available for anyone else). The person running the Barbarian can then look at the item when there is free time to decide whether to use it. And I'd say we don't worry about returning unwanted items. They just aren't worth that much. If you decide you don't want it, then vendor/break it down.
I failed to comment on this but would like to. I try not to be uptight but I can't help it at times. A fair bit of income comes from selling items. I fully admit your way is way better for speed and ease, but I don't want to be throwing away cash in case someone needs something. I get a bit twitchy if I don't think I'm getting my fair share. It sounds worse than it is. I'm not greedy at all, but it would drive me to distraction if we all adopted the picked up and drop technique and I started to think everything was being picked up and vendored by a single player. I don't want more than my share, but I don't want less either. Consider it a quirk. Even if I agreed not to worry about it, and didn't worry about it consciously, my sub conscious would be keeping an eye on things. It sucks. Sorry.
Not sure how others feel about it. There is certainly a lot going for the Mix's idea.