I hear a lot of people who reflexively disbelieve anything Obama says too: it's because they've decided he's a liar, not because he lacks the moral courage necessary to turn himself in for his admitted drug use.
Digression:
I do not myself care that Obama used drugs. I think those drugs should have been legal. I think it was courageous of Obama to admit to drug use even if he did so in a way that did not lead to legal repercussions.
But I also do not care that Snowden violated the law in his whistleblowing. I think his whistleblowing should have been legal. And I think it was courageous of Snowden to blow the whistle, even if he did so in a way that did not lead to the most severe legal repercussions possible.
End digression.
But no, I do not think that I made an analogy, nor that my observation was flawed. People who say, "I won't listen to Snowden unless he turns himself in" are not making an argument about Snowden's facts, they're making an argument about his character. They're saying, "I won't listen to Snowden because he isn't willing to suffer every possible negative consequence of his actions." It doesn't matter if his actions were related to the spying or not.
Those same people never demand the same of Obama (or any of the other government representatives). Those representatives can, and do, in fact, grant themselves and their allies full immunity from negative repercussions, and are still treated respectfully. This is hypocrisy on the part of those who demand that Snowden turn himself in.
And finally, if you want an example of Obama's less-than-perfect moral character that directly relates to the matter under discussion, there is his claim that he was against warrantless wiretaps, and campaigning as someone who was against them.