From the IG's report, we found out for the first time that Hillary's server came under attack from a hacker. Given that classified information existed on the server at the time, and Hillary should have known that that, it was grossly negligent of her not to report the attach to the State Department IT people as well as the FBI. Personally, I think that is an unforgivable breach of duty, and I doubt that people in the FBI's computer security area would think differently. The only thing worse from a security perspective than allowing classified information to fall into the hands of our enemies is to have that happen and not to know about it. Hillary's actions (and inaction) exacerbated the risk of that happening.
Also, I would revise your last sentence. The only reason that Hillary might not be indicted is that she is the presumptive nominee of the Democratic Party. People would care whether or not the person undermining our national security were famous.