Charles Lamb wrote of Shelley: “His voice was the most obnoxious squeak I ever was tormented with," and James Dickey, poet and novelist, said of an iconic New England poet: “If it were thought that anything I wrote were influenced by Robert Frost, I would take that particular work of mine, shred it, and flush it down the toilet, hoping not to clog the pipes. … a more sententious holding-forth old bore, who expected every hero-worshipping adenoidal twerp of a student-poet to hang on his every word, I never saw."
(Dickey's overdoing it... I think if you're to write an insult it has to be short, to the point, and maybe not seem like an insult at all at first... leading to a kind of double-take, followed by surprised indignation and affront - is that what he said about me?)
It's also funny to me that authors whose works may contain such depth and nobility can also behave like snotty kids to one another in real life.
And writers insulting one another reminds me of the Shakespeare Insult Kit:
Thou pribbling knotty-pated flax-wench!