At the very least, it leads to even more divisiveness, instead of rational discussion.
As a thought experiment: have you ever seen someone change their mind or worldview as a result of being insulted & fired?
Too many, all across the spectrum, have his mindset that people that do or think things they don't like should be destroyed and locked away from "civilized society." A common rebuttal I see from these sorts, after being questioned why they don't take it upon themselves to sit down and understand one another (I will concede there is a very very very small minority that this shouldn't be done with, but you're unlikely to ever interact with them), is that it's not their duty to help these people.
Unfortunately, this makes the issue worse when you start exiling certain groups and radicalized with hate.
Here's an interesting article (isolated incident) where those with extreme views were shown compassion and understanding, and ultimately disavowed their ideas:
Black Man Gets KKK Members To Disavow By Befriending Them: http://www.huffingtonpost.com/entry/black-man-daryl-davis-be...
I have see people limited in their ability to cause further harm by being fired; not all consequences are directed at reformation if he offender.
...but that's not why someone in this position would be fired. It would be because their publicly stated opinions about what people are and are not capable of makes their co-workers deeply uncomfortable.
We can debate endlessly (we already have, I'm sure we will again) whether firing is the right or wrong choice, but let's argue about it for the right reasons.
It's fundamentally not about them; it's about their co-workers. Making it about them is the wrong approach.