Yeah, I think everyone has that kind of perspective (prioritizing rehabilitation less and punishment more for murderers and rapists, etc.). But it's a hard line to draw and is likely more costly than it is worth.
For me, personally, I think rehabilitation is worthwhile for every criminal, with the lone exception perhaps being aggravated rapists. For instance, pedophiles actually seem to respond better to rehabilitation than the average sex criminal. But.....man, if you are a person who can violently rape another person at knife point, etc......I just don't know that you can be reasonably converted into a productive citizen. But that's just me.