Just like Snowden, Manning would have been treated as a whistleblower if he had only leaked illegal or possibly illegal things the government did. Instead, he dumped a full archive of secret diplomatic cables. That's not as bad as Snowden, who deliberately leaked Chinese targets to China in hopes of getting asylum in Hong Kong.

Why is the focus always on what these people did, and not on the crimes that they exposed?

Why are you saying "if they had done it differently they would be treated better" instead of "I am ashamed of the evil and illegal acts that my country has done and want to change the system to make this impossible"?

Why do you care what either of them did more than you care about what the government did?