The reasons Clinton lost are quite obvious to any objective observer, and have little or nothing to do with gender. Clinton simply failed to connect with the average voter. To put the same thing another way, she failed to articulate any compelling reason for why she was running for president, and hence, for why anyone should vote for her.
Clinton lost because she came across as stiff, stilted, dull, boring, robotic, lacking in spontaneity, uninspiring, lacking in passion, uncomfortable in her own skin, unable to think on her feet, and without a sense of humor. This observation has nothing to do with gender--many male candidates have suffered from the same type of problem (Jimmy Carter in 1980, Michael Dukakis in 1988, Al Gore in 2000, and George Romney in 2012, to name a few recent ones).
I will be glad when politicians and the media get away from this whole "identity politics" obsession, and start focusing instead on real issues and honest evaluations of why voters vote for a particular candidate. And yes, like it or not, "likability" is a big factor, regardless of gender.