Tracy Orbison is such a sad character. He's overweight, naive...and depressed, but optimistic. The combination of those characteristics makes this movie hard to watch. You want to root for Tracy, but then he's just so naive about a situation you can't...or he's so optimistic about something that you just feel sad for him, and he has sort of this babyface that just makes it harder emotionally to watch.
Although the overall theme of the movie is hopelessness...there are little bits of humor and resolution that keep you going just enough to get through to the end.