That's like asking why drivers are "allowed" to break the speed limit!
Sellers are not allowed to use registered brand names to describe fakes or copycat unbranded products. That doesn't mean that some sellers won't break the rules.
There is a link in every listing to report it. You can use this, but dont be surprised if no action is taken. Reports of brand name misuse from ordinay members are not always reliable and amay even be malicious. eBay will remove the listing immediately if the brand owner reports it - which the big brands do on eBay, all the time.
