If your notion of justice doesn't include retribution, that's completely legitimate, but to insinuate that your sense of justice is somehow less of a emotional response than someone else's is ridiculous.
I would think that there should still be some period of incarceration as a putative measure.
If an individual is dangerous for society they shouldn't be in it, this doesn't mean forever if there is a possibility of rehabilitation. There are many monsters locked up that probably should never be released, in that sense the justice systems of Norway, Germany, Sweden and others work well: you are locked up to 20 years, after that your case is reviewed and if you are still deemed a danger to society you get it prolonged, a few times this goes on for life.
If you were taking some position about money management and the response was "Yeah, just wait until you when the lottery" you wouldn't see this as a threat. Try reading it in that sense.