I've not read much of Holmes, so I can't really speak to the original character, but I would point out that the "he can socialize, he just doesn't like to" bit is somewhat part of BBC's Sherlock too - look at the relationship he developed with the woman to get at Magnussen. It's an aspect of him they never really explored much beyond that though - you're definitely right in that he seems more incapable of it than anything else.