Because it's paypal. Bitcoin is opposite to it. It's not controlled by any government. usa can block Bitcoins but other 200+ countries will still accept it. Believe me - if a lot of people join Bitcoin in USA there will be nice fight on the streets if it will be disabled/blocked in their country.
Ofc Bitcoin have some central points - like irc, main places of exchange(mtgox) and for example website is posted on some web server with specific ip(but also on SF), but remember - irc can be replaced, server can be replaced(or even software can be distributed via p2p in torrents for example) and mtgox is in Japan, if he disappear then price will drop, but bitcoin will not disappear : )
Bitcoin can't be controlled just like that. They would need to close mtgox, put gavin in jail and close half of the internet. GL with that.
Time will show us facts.
Anyway -
It's a revolution. Go bitcoins!
btw. - epic: