A loner, hermit, or someone who purposely isolates themselves from others might represent:
A need for more "alone time" or time to oneself
More focus on oneself, one's own needs, or other aspects of the inner process
Independence, or a desire for more or less independence
Perceived tendencies for isolation, misanthropy, or anti-social feelings attributed to another person
Not wanting to participate in society, or wanting to act against it