Not that I approve of either one, but there IS a big difference between pedophiles and ephebophiles. Pre-adolescent children never enjoy sexual relationships with adults, and thus someone who likes to have sex with them by definition likes hurting them, frightening them, etc. On the other hand, 14 year olds (of both sexes) often try to initiate sexual relationships with adults, and/or are very flattered when an adult initiates a sexual relationship with them, and often enjoy the sexual aspect very much. So an adult who's emotionally stunted or for whatever reason unable to form sexual relationships with adults, may prefer adolescents, and it may be very important to them that the adolescent seems to be enjoying it. It's not a bit healthy for either the adult or the adolescent, but it's not monstrous on the level of an adult forcing him(or her)self sexually on an unwilling, uncomprehending, and terrified child.
Perhaps that's why the sentencing guidelines are different.
An excellant, informative post. Thanks. There is a difference in psychological development. You're right though, "less bad" doesn't make it ok.