Do we seek authorial greatness?

The following lines are excerpted from Charles McGrath's New York Times Book Review of Muriel Spark:  The Biography (Martin Stannard, W.W. Norton):

Reading between the lines of Stannard's book, one concludes that like a lot of great writers, Spark was actually a bit of a monster—a charming, appealing monster but a monster all the same, willing to sacrifice everything for the sake of her work.  She was a neglectful mother; a mercurial and inconstant friend who 'went through people like pieces of Kleenex,' according to the writer Ved Mehta, who knew her in the '60s; a bully to agents, editors, and publishers.  As we would say today, she was very high maintenance.  She behaved, in short, like any number of male writers, including ones much less talented than she, but as a woman so ruthlessly and coldheartedly in pursuit of her art she was a little ahead of her time.

(Might I simply say, for the record, that I've met writers of all kinds.  Some of the very best turn out to be some of the very nicest.  But that's just me.  I've encountered the other sort, too.  You don't find them on my blog.)