Of course they're not. They're destroying goods that they can't sell at a profit because, for example, the cost of processing some unworn but returned goods outweighs the potential profit from those goods.

In TFA it's estimated that between 4% and 9% of clothing put on the EU market is destroyed before being worn. An admittedly high uncertainty, but even 4% of all clothing sold in the EU is still a heck of a lot of clothes.