Why is it, then?
Why is it seemingly impossible for a new Administration's Attorney General to cut through all this bullshit?
Why is it possible for Barack Obama and Hillary Clinton...Valerie Jarrett, Susan Rice, James Comey, et al...to be walking the streets and not under arrest?
i mean W. T. F. ??? 
How can people still believe that humans are warming the planet to catastrophe, when we've passed the appointed apocalypse several times over with little noticeable effect (except that winter storms now have names, too).
An old sheriff told me once, "If the paper work never gets filled out, nothing happened."
When the administration is dealing with investigative entities which have been stacked with compromised political operatives who failed to prosecute the obvious crimes being conducted under color of law, including their own mis/mal/non-feasance, when the whistle blowers were either few and far between, and when there were 'examples' of what happens if someone doesn't follow the code of
Omerta , few will stick their heads up, and those will be disposed of or ignored, the paperwork won't be filed, the charges won't be brought, and the investigation will issue reports finding nothing amiss before the witnesses are even interviewed.
The Media will cover for it all, with smokescreens of pop icons (which the media made 'icons'), orchestrated displays of outrageous stupidity or hateful statements designed to fill the column inches and precious seconds between commercials. Failing that, someone will be getting a kitty out of a tree, helping a little old lady across the street, and what looks like a 'slow news day' will actually be the usual robbery, murder, and mayhem behind the smokescreen.
Failing that, saturate everything with cute cat videos.
The whole goddamned mess is corrupt. It's big money, it's international, it's from the top levels down, and includes members of both of the major political parties.
That's why nothing is getting done. That's why the whole band of 600 lb gorillas in the room are being sidestepped while the investigators crawl around the floor making big noises about looking for an orange hair.
You don't find what you won't look for.
Recall, the first, best defense of both the Clintons and the Obama administration was to commit crimes that read like a 'conspiracy theory' plot, that way they could be blown off as such by the media, the people who sorted it out marginalized (Alinsky'd), and the whole criminal juggernaut rolls on, pocketing money from relief efforts, running guns to criminal Cartels in another country, selling Uranium reserves to potential enemies, even sacrificing an ambassador to cover gun running in the Middle East.
But the front people in this are worth hundreds of millions, and their backers worth adds a few zeroes on the end. Others who were prominent enough to speak out and blow the lid off suffered 'problems' like Ron Brown's plane running into the mountain on a clear day--and Ron with a .45 caliber hole in his head, or Loretta Fuddy being the only one to not survive the plane crash, even though she got out alive and visibly unhurt, within swimming distance of the beach and a wearing flotation device.
Being in a position to be a key witness, possessing evidence, telling tales out of turn all seem to be hazardous to the health of the people who have been there, victims of 'botched robberies' where nothing of value was taken (that we know of), plane crashes, heart attacks on the street after breaking bread with the enemy, and other causes that ultimately make the COD of "Heart Failure" true, no matter what caused it to stop.
Nope, without a fresh bunch of investigators, a clean organization without ties to the previous ones, nothing is going to happen. Even with that, there will be the endless litany of "I do not recall", invocations of the 5th Amendment, and assertions that "...there is no evidence which exists..." (Because the people who should have preserved the crime scene let it burn--and 'lost' key pieces which should have survived even that holocaust).
How many months did Congress spend looking at black pages of subpoenaed documents, redacted to uselessness and re-requesting the actual information? Even then, the people who refused were not incarcerated for contempt, as Congress can do, but skated as they stalled, running out the clock on the session, and GOP control--something tenuous at best with the almost predictable desertion from the ranks of key voters on key issues.
You tell me. How do you get past all that to prosecute those who are so deserving without something unconventional, and once that genie is out of the bottle, how do you put it back in?
I fear, that one way or another, we're going to have a "fundamental transformation" here, and the folks who couldn't push it past the goalie are waiting for the other side to knock it in.