The reason there is no good alternative to PayPal, and especially an alternative that works internationally, is the regulatory environment around money transmission in the United States. If startups expect to solve this problem, there needs to be a coordinated effort to change that environment just as there was a coordinated effort to combat SOPA.
Exhibit A - http://www.thinkcomputer.com/corporate/whitepapers/heldhosta...
Exhibit B - http://www.plainsite.org/flashlight/case.html?id=716056
Exhibit C - http://www.plainsite.org/issues/index.html?id=1
Exhibit D - http://www.leginfo.ca.gov/cgi-bin/displaycode?section=fin...
To head off the most common objections: PayPal is grandfathered in at this point. You can only get away with breaking the law and hoping no one will notice for so long. The penalties for violation are criminal (federal felony), not civil. And yes, I'm biased as the head of a payments company affected by the law, but I'm not the only one, and I'm not wrong.