Ebay monopolizes the auction market in the US so 
it can only increase revenues by expanding into 
new markets. This policy paves the way for 
redirecting customers and vendors to stores run 
on/by Ebay. 

It's within their rights to implement the policy 
because it's their money, just like you can 
refuse to go along since it's your money/goods. 
If enough people complain or boycott, the policy 
goes away. 

Public companies exist to benefit shareholders, 
employees, and customers - pretty much in that 
order. It sounds harsh, but customers are a means 
to an end and not the end itself.