Rapists

[Jackalope]

Justice systems are limited. Not all who have committed a crime will be prosecuted for a crime, and not all that are prosecuted will be convicted. It sucks, but a potential alternative may be worse.

And indeed, not all who are prosecuted and convicted are in fact guilty.

As you say, potential alternatives may be worse. The "western" system of justice is far from perfect, but we could do much, much worse, and it's not clear that we can do much better.