Because men with power don't want anything free left, and the internet was the last great free frontier.
Just wait will you have to pay tax for regular peer to peer paypal transactions.
eBay has been fighting this for 5 years, I know most don't like eBay, but support them if you want a free marketplace.
and yeah if you live in the US, it doesn't matter what you declare, you don't pay duty or tax on imports.