I first noticed this in "House." None of the characters seemed to bathe regularly. Shiny hair and faces on the women, three days growth of beard on the men.
It got worse in "Lost." I understand that the characters were roughing it on an island. But in the flashback scenes they still needed to wash their hair and shave!
I've noticed it in a lot of movies recently as well.
Last night I watched "Emily Owens, M.D." and poor Mamie Gummer looked like she hadn't touched her hair in at least a week--it was so stringy and greasy!
When and why did this become an "in" style? I know from personal experience, growing up with very oily skin and hair, that not only is it unattractive, it is uncomfortable because your hair feels heavy plastered against your head.