This is going to sound so bad, and I am so sorry, because I want to give an honest opinion, but there's no nice way to say it.
From what I've seen by going to conventions/seeing posts from people/general online and personal knowledge, it seems a lot of anime/manga fans act like loud 12 year olds. They're not afraid to act out in public and say some...odd things in social situations, and I believe that could lead them to being ostracized/having few friends/being made fun of. As to why these type of people are drawn to anime/manga, is something that is probably really complex. It may be that it draws people in that are already different, and these people view it as different, so they watch it. It could be for the action/romance that they want their life to be like. I don't know. I know the reason I like anime is because they are somewhere in between cartoons and non-animated movies/shows. It has a complex/interesting plot, can be serious/not serious, looks pretty, have unrealistic things happen in them, are unique, and make me think 'wow, I wish my life was like that' or 'that's/they're so cool'.
From what I've said, I don't mean to offend anyone. I'm an anime fan, too, so I know we're not all like that. Just speaking from person experience.
Also, the statement about having more time to go on the internet is good explanation.