This is the most logical answer. When people wonder about the impropriety of the meeting, what comes to mind is his extraordinary exceptionalism.
He was the first presidential candidate to admit to smoking pot, and was still elected. This seems like nothing now, but even strong hints of smoking pot pre-Clinton was enough to stop candidacy for any public office in its tracks.
He fucked extramaritally with reckless abandon throughout his long political career, and while he most certainly wasn't alone among presidents to enjoy this hobby, he was the first to be nailed to the wall and caught lying about it under oath. CEOs and bosses at every level were being fired, tarred, feathered and socially beheaded for even flirting with women in subordinate positions at the workplace, but Bill has a longish-term sexual relationship with a kid, wags his lying finger at the country and keeps his job.
He begins to see himself as above the law. He's blameless. He's impervious to mortal rules.
He controls the enormous black voting block - don't underestimate the power and significance of this little sentence - after gutting welfare and selling out the needs of the poorest sector of the US, which happened to be carved out of black America. His brainchild, prison-for-profit, has laid waste to the black community for decades, but they either don't know or don't care. He grins and they fall over themselves to do his bidding at the polls.
He is not just above the law, he's an immortal.
Smart man, he devised a way to make billions in "public service." His education came in quite handy. A "Foundation" where money comes in in the form of charitable contributions. The president who defended himself by responding about the definition of the word "is," knows that proving 'pay for play' is almost impossible without an admission of guilt. Brilliant.
His wife is forever on the edge of indictment but either pay-off, threat, cronyism, or prosecutors aware of burden of proof in a country where Clintons can afford headlines isn't worth the considerable trouble and personal and professional risk.
So, hell. How do YOU feel if you're Bill Clinton? Untouchable. Like Al Capone. Until you finally make a mistake and get what's coming to you.
May it be soon.