That means you're a bad person. The people who agree with you are also bad people.
You also aren't thinking this through at all.
What happens to the person who rapes the rapist or child molester? They're a rapist now too. They are someone who is genuinely able to rape and is sexually satisfied by rape. We can't just let them continue their lives as normal, they are undoubtedly a rapist. They will keep raping. That's what rapists do.
That's the whole thing, there aren't actually that many rapists out there it's just the rapists that are out there rape constantly.
Do we declare that some rapists are good rapists and don't need to be punished for their rapes? How do we decide which rapists are the good rapists and which ones are the bad rapist? How do we make sure the good rapists stay good?

You are a bad person if you try to justify rape.
We're all here reading this and being titillated by rape. That has its own moral implications but we certainly can't judge each other for that...
However, there's a big difference between being titillated by something you know is wrong and trying to pretend that something wrong is somehow right.
All rape is wrong. There is never a rape that is justified. Even rapists and child molesters should not ever be raped. Rape should never happen. All rape all the time should never happen to anyone for any reason.
There is no justification for rape.
Think about this logically. If we rape rapists we just create another rapist who now needs to be raped. Who's going to rape the rapist who rapes rapists? Because whoever does becomes a rapist and now needs to be raped, it's just endless rape. It creates this endless cycle of harm. Where the person giving out the punishment harms themselves as much as they harm the person they're punishing and now need to be harmed in kind.
This doesn't mean that rapists and child molesters shouldn't be punished. We should put them down like rabid dogs. We shouldn't torture them. We shouldn't rape them. We shouldn't make ourselves less in order to punish them.