We do not know why. It is not an institution expressly for the purposes of educating criminals, but many with the pathology of the criminal -- sociopaths? -- are drawn to this institution of higher learning special connections.
We were all entertained by Elizabeth Warren's claim that she is of Native American ancestry, but she is just a scrub lying to get ahead. Harvard really caters to the extremely wealthy, like Jeffery Epstein, Bill Clinton's close friend and favor provider. The wealthy need politicians to help them avoid punishment for their crimes. (Side note: Does it get much worse than the pass Ed Buck has received?)
The relationship for some of these players has become perverted enough that The Harvard Crimson has covered a specific incidence with their flexible purchasable standards: Billionaire and Convicted Sex Offender Jeffrey Epstein Boasts Deep, Longstanding Ties to Harvard
Who cares? Not many. But dangerous people have associations that we should all learn from, whether it be to become wealthy or protect ourselves from the consequenceless wealthy. A lot of people are not good, and if hearing an association with Harvard suggests a mindset beyond consequences, be on alert.