I think it's a lack of self respect. I personally feel a lot better after a shower and take them regularly. Other than the obvious cleaning yourself, I find they are great for waking you up in the morning, and relaxing you at night before going to sleep.
Some of it depends on culture. My husband had a business associate several years ago from Belgium. He was wealthy and sophisticated, yet he bathed only once a week. Several Europeans have told me that they think Americans are too obsessed with bathing and showering.