|MadSci Network: Neuroscience|
Durian is a fruit from southeast Asia, known for its strong odor. As you describe, some people find the odor fragrant, others find it offensive and digusting describing it as rotten eggs, turpentine or gym socks. So you're correct that some people find the smell offensive and others like it.
Different people have a different combination of odor receptors in the nose. Humans have about 350 different functional genes (compared to about 1000 in the mouse). Each of the genes can have several different variations. Because of the different variations, different odors smell differently to different people. In addition, depending on culture and other differences people experience growing up, different smells may be associated in the brain with good or bad experiences. So, because of different variations in our genes and because of different experiences growing up, people may experience the same odor differently.
Thank you for your excellent and very observant question.
You can read more about human smell at these links:
From How Stuff Works: http://health.howstuffworks.com/human-body/systems/nose-throat/smell.htm
Your Gross and Cool Body: http://yucky.discovery.com/flash/body/pg000150.html
Try the links in the MadSci Library for more information on Neuroscience.