I don't think he's a hypocrite. He may run his organization in an authoritarian, despotic, and un-transparent way, but in the end, the people working for him are there voluntarily. While some of his actions may put people at risk, in general, wikileaks doesn't directly put people in jail, assassinate people, or otherwise impinge on people's civil liberties. So the moral responsibilities of Assange are fundamentally different from that of the United States government.
It would, however, be hypocrisy, for example, if the president of Ecuador, for example, saw fit to criticize the US (unless Ecuador is a saintly state, which, I doubt).
Fundamentally, both Assange and the US government face the same issue: how to balance the privacy of individuals with some greater need. In the case of the United States, it's national security, in the case of Assange, it's his feeling that government needs to be held to account. The people who helped American forces in Afghanistan or talked to American diplomats have the right to have their personal conversations kept private. Wikileaks violated that right in the name of a greater good. If Assange wants to criticize the United States government for violating the rights of Verizon customers to the privacy of their calling information without due process and the rule of law, he should seriously consider whether his own organization did a good job of protecting the privacy of thousands of people because either through conscious decisions (releasing the Afghan war logs unredacted) or negligence (leaving copies of the unredacted cables on publicly-accessible servers, allowing seriously dodgy people like Israel Shamir access to unredacted cables) that information got out. What due process did Wikileaks give people named in leaked documents? When the cables were being released it wasn't even possible for me to contact Wikileaks to get them to redact names on a cable that were accidentally left unredacted.
I think most sane people disagree that the right to privacy is paramount when it comes to who is setting and influencing US military policy.
That said, it is worth remembering that more people had access to those records than are members of the Chinese Communist Party. So if the information was particularly sensitive (and it does not seem sensitive, raising the question of why so much was classified) the question is why it was classified for general distribution.
"The people who helped American forces in Afghanistan or talked to American diplomats have the right to have their personal conversations kept private."
Then their privacy had already been violated, because the state department diplomat had already forwarded those conversations to others within the state department.
It would, however, be hypocrisy, for example, if the president of Ecuador, for example, saw fit to criticize the US (unless Ecuador is a saintly state, which, I doubt).