Well, not that I have the time to make a detailed argument but here are some points to consider.

1. First you have to define what "taking advantage of children" means. Is a child molester the same as a rapist? Then you have to define what "severely punished" means. Is everyone going to jail for life for touching a child regardless of circumstances?

2. If the punishments for varied intensities of crime (all of which fall under child abuse) get different severities of punishment by what logic do you justify life in prison? How can you justify that severity of punishment when murder often does not result in life in prison?

3. If the sex is consensual, but illegal as in statutory rape, does the person still get life in prison? Who are you to destroy the life of a person who caused no harm but ran afoul of the laws? Not all statutory rape is the result of grooming, coercion, and harmful. Should there not be a court case to determine the exact amount of harm and have a proportional punishment? Do you send two teenage lovers to prison for life?

4. How do you justify life in prison for touching a child when far more harm can be done to the child in other ways that are not sexual? Is all harm done to a child automatically lead to life in prison?

5. How do you justify abandoning the tenant of "the punishment should fit the crime"? After all, life in prison is a punishment that take someone's life away. You can't claim that rape and death are proportional.

6. How do you justify having hugely disparate punishments for the same crime based on the age of the victim? How does molesting a 17 year old get you life in prison but molesting an 18 year old gets you kicked off the football team?