"stopping" people from attempting the nearly impossible is not advise. It is more of discouragement. Hope you don't tell your children to limit their dream because they are doomed to fail. If failure was my goal, you just gave me a real push.
In a group such as this, where people are purposefuly trying to push the limits, i don't think it's good to discourage anyone. I think it's ok though to tell people, especially growers with not too much experience, that a certain plant, like durian, is a very difficult one to grow way outside it's normal zone. This so they don't get too discouraged if they fail. Durian is especially difficult for many different reasons: seeds large, very perishable, and delicate. Scion wood very perishable, lasting about 2 days. Plants can't stand to be bare rooted. Grafting difficult for unexperienced, approach grafting being the easiest. Susceptibility to root rot and other diseases. So even for professional nurseryman this is a very difficult plant to grow and establish outside of the tropics.
All that said, actually growing durian outside of tropical range is not all too difficult. I think many people can have a durian house plant in heated/humidified environment, at least for some time. What is very very difficult is to fruit it outside of the tropics.