While I agree that there are some fanfiction Darcys that are pictures of perfection, I don't think it's as usual as a perfect Elizabeth. Mainly, I think, because an unrealistically-perfect-Elizabeth is perfect in all respects (appearence and intelligence and accomplishment and character), while unreallistically-perfect-Darcy is perfect in appearence and intelligence and accomplishment, but stil has character flaws (he used to be a rake, he is a snob, etc.).
By the way, I would say that Darcy being drop-dead gorgeous and not merely handsome is canon; he walks into the Meryton Assembly and everyone, men and women, comment on his good looks. What is absurd is the usual portrayal of female reaction to his looks and position and fortune. Yes, a handsome man with aristocratic breeding and connections and a fine estate and 10,000 a year was a very elegible prospect. But he was not the best catch in England, especially for ladies of his own social circle, some of whom would be his equals in these things; his income is actually middle-of-the-road for the upper-class. For, say, a wealthy and influential Duke's daughter, Darcy is nothing more than a respectable suitor.
By the way, I would say that Darcy being drop-dead gorgeous and not merely handsome is canon; he walks into the Meryton Assembly and everyone, men and women, comment on his good looks. What is absurd is the usual portrayal of female reaction to his looks and position and fortune. Yes, a handsome man with aristocratic breeding and connections and a fine estate and 10,000 a year was a very elegible prospect. But he was not the best catch in England, especially for ladies of his own social circle, some of whom would be his equals in these things; his income is actually middle-of-the-road for the upper-class. For, say, a wealthy and influential Duke's daughter, Darcy is nothing more than a respectable suitor.