I believe the article is referring to those that miss the company of others. Those that are lonely. There is a definite difference in being alone and being lonely. Solitude can be a very happy and relaxing place. I, for one, love my time alone and my time with people.
As for who is more susceptible to loneliness, men or women? I would venture to say, like everything else, the statistics will show more women. That is only because men are not as likely to admit they are lonely, just as they are not as likely to admit they are depressed, suffer from panic attacks etc. When men suffer from these conditions they are affected more severly than women because they involve their "ego."