Bryan Appleyard reviews the entire science fiction genre when he reviews The Invisible Man in New Statesman – Books:
Between 1895 and 1898, H G Wells wrote four science fiction masterpieces — The Time Machine, The Island of Dr Moreau, The Invisible Man and The War of the Worlds. Then, as now, SF was seen as not quite respectable by literary types. The vile George Bernard Shaw sneered at Wells, and even his own literary patron, W E Henley, told him: “You could also do better — far better & to begin with, you must begin by taking yourself more seriously.” In our day, Margaret Atwood has turned her nose up at SF, preferring to call the novels she writes “speculative fiction”, a truly toe-curling piece of petty snobbery.The ratio of bad to good SF novels is about the same as that of bad to good literary novels, but, for some reason, SF is always judged by the output of its most inept practitioners. In truth, a form that has produced, among others, Stanislaw Lem, J G Ballard, the Strugatsky brothers and, above all, Herbert George Wells has nothing to apologise for.
I don’t know how you can fail to follow that paragraph with a description of Sturgeon’s Law:
Ninety percent of everything is crud.
It was originally stated as a defense (of sorts) of science fiction:
Sure, ninety percent of science fiction is crud. That’s because ninety percent of everything is crud.