People used to go to the bin at the nurseries to pick up the thrown out plants. Well, the neighborhood nurseries realized this and started dousing their plants with weed killer when they put them in the bin so whatever you picked up would be dead in two days. That is wasteful. Amazing. Why didn’t they discount them or replant into larger containers, I can’t tell you.
part of it is lawyers and part of it is they figure you are more likely to come in and buy something if you can’t get it for free.