Charlie is sympathetic because the circumstance of Nicole taking Henry to California and filing for divorce there puts most of the cards in her deck in the legal fight. Charlie realizes he is screwed when he talks to the first lawyer. The movie is not half over then. Charlie is the loser here, Nicole the victor with majority custody of the son in California with her new partner, better job and extended family. Good for Nicole, not as good for Charlie. The lessons are all still there even if Charlie's character seemed more interesting to you.