If it's only about the smell you can simply buy a copy. I agree with you but it's why they do it and some people lap it up
Copies are never the same though. They sometimes come close to the original smell but more often than not there are miles away or a nasty aftersmell or dont last as long as they have cut corners on the ingredient which makes it last long etc.
Its like with copy watches. I have seen awful ones for fiver where the make your arm go green and decent quality ones for £250 which you would be hard pushed to tell the difference between the original and the fake.
But you are right, people lap it up. People buy fragrances purely based on which celebrity is paid millions to endorse it. Some buy them purely because they love the bottle.
Its the same with diamonds. If diamonds were a true free market and only cost a few pounds to buy then the demand for diamond jewellery would plummet overnight.