Whistleblowers act against power structures and that's the ultimate transgression as far as the power structure is concerned. Transgressions in favor of the state are one thing, you'll get a slap on the wrist at most, even personal benefit and promotion in some cases, but transgressions against the state are what will provoke a real response. See, for example, the incredible vigor pursued against the people who relea…
What makes it worse is, whistleblowers are trouble makers often. They are difficult people, at best like Snowden, they lay low. It makes it easier to dismiss them. Why? Because people who are good and social with the group do not have a contrarian character. To whistleblow against a very powerful organisation, like the NSA, you have to be a pain in the ass. I don't mean that in a bad way. Normal sociable people just…
You're making way too simplistic a generalization here. Some sociable people can be sociable and friendly with a group until that group changes and they decide that it no longer fits their morality. They can still be contrarians, and then make waves anyhow. You absolutely don't have to be an introverted, hard nosed loner to end up being a whistleblower or contrarian troublemaker. This sounds a bit more like wishful fantasy for people who are socially inept trying to paint it as more noble.
If anything, a sociable, open person is more likely to have the kind of self assured personality that makes them decide it's not a problem to disagree among their peer group whenever it becomes necessary. Read more history, it's full of troublemakers who were also sociable.