1) Dostoyevsky is insanely moralizing and can't tell a good story. All of his characters are one-dimensional, have a "revealing" name and exist only as an excuse for a sermon...
His short stories, less known here, are good, though.
Turgenev: a writer who vehemently believed that women can never have sex, probably because he had such a good time having sex with birth trees, judging by his interminable and spectacularly dull descriptions of nature that we were tortured with in school.
He is greatly redeemed by the fact that he was tremendously insane and died a raving lunatic.