Partly because it is easier to brainwash someone than to convince them that they have been brainwashed. Ego blocks that information. In college, they learn that it is only their superior intelligence that allows them to understand the value of Progressive values. They are stroked constantly this way. It's almost impossible for them to let go of this feeling of being a member of a sort of intellectual aristocracy. It's the link between their lip service to equality and their deep, hidden fascination with class.
Yes, flattery... to be first amongst equals. They believe they belong to a privileged class despite the lip service to equality. That’s why their greatest fear is to be ostracized from the class or party and why the democrats march in lock step. It’s seems that the contradiction (first amongst equals) doesn’t bother them and they perhaps believe (at least leftist thinkers like Heidegger do) life is inherently contradictory at it’s deepest levels. That allows them to have their cake and eat it: to be rich and say they are morally superior because they are concerned about the poor. It’s like millionaire Bernie Sanders or Michael Moore say they are socialists. In the end, I just find it that they are very greedy to want your cake and eat it. The word hypocrisy has no meaning for them... or, at least, no bad meaning.