While I tend to agree, it's a little like telling someone to just "find a better job"; it's not always so easy. Maybe some people are unfortunate enough to not have real friends, and shallow Facebook connections are all they have.
Even though the shallow connections take up time that could be spent forging more meaningful connections with those around them, not everyone is self-confident enough to go cold-turkey.
Because if ones friends forget to invite them to events because they are not on FB, then it’s time to find new friends.