It's not that the manufacturer can't sell their product, it's that they don't want to do so. They want to get rid of last season's perfectly good product to make room for next season's lineup.
They could sell old stock ay reduced prices and still make profits, but they want to maintain their vain exclusive image, so they inflate their prices by destroying stock.
They could sell old stock ay reduced prices and still make profits, but they want to maintain their vain exclusive image, so they inflate their prices by destroying stock.