Yes I remember the yard sales too. Mostly they were eyesores that people placed out in an effort to make money off the the stuff they collected.
Copy only and Copy no transfer work because the induce people to continue to by while not burdening the seller/creator with reparing peoples 'mistakes'.
It also allows SL to control the flow of trademark violated items and copyright infriged items both of which the world is filled with, I actually had to edit an Item I see because someone got angry that it doesnt exist IRL. He failed to understand that real world items require rights and companies won't just give them to you on whimsy.
Sorry that gatcha seems to have exploded and killed yard sales.