Barbara Walters made a promotional stop on Letterman on Tuesday, where she attempted to explain the inexplicable: How Donald Trump and the collective Kardashians earned a spot on Walters' The 10 Most Fascinating People of 2011.

On the one hand, the self-absorbed, self-promoting, publicity-stunting reality stars (including Trump) didn't contribute anything meaningful to society this year; they might have actually detracted from it by cheapening the institution of marriage and making shameless self-promotion appear acceptable. "You cannot trust the Kardashians," Walters said. And on that other hand, despite misgivings, they still get attention, and profit from it.

Walters' special Barbara Walters Presents: The 10 Most Fascinating People of 2011 airs on Wednesday, December 14 at 9:30 p.m. ET/PT on ABC.

Still trying to get a nasty note from Trump.