Name given to Men's Underwear 'ComfyBall' is rejected in the U.S for Trade Mark

This men's underwear brand named Comfyballs is not permitted in America, says the U.S. Patent and Trade Office.

 

The agency has denied the Norwegian company's application to register the trademark in the U.S., calling the name 'vulgar.'

The company was born in 2013 and quickly moved to the UK, New Zealand and Australia where it promises its underwear--designed with PackageFront technology--reduces heat while allowing for freer movement.

 

 

Price is around 40 dollars even though its not yet sold in the U.S Officially.

 

My questions, what's wrong with the name? Because the agency effused the 'balls' attached to the name.