I think the idea that society is becoming more tolerant, except for intolerance, is really interesting. There was a lecture at my university about how an increasing number of campaigns/policies are denying freedom of expression under the guise of preventing intolerance - things like campaigns to stop selling The Sun because of page 3, and not giving a platform to far-right speakers (including racist speakers, Islamic extremists).
I think it's a difficult problem for me personally (to think about), because I want to balance maximising peoples freedoms with stopping the infringement on other peoples freedoms and encouraging hate, discrimination and institutional racism/sexism.
On the whole, I tend to err on the side of maximising peoples freedoms - I think it's dangerous to stop people deemed "intolerant" or discriminatory from speaking/expressing/sharing their views. Most importantly because I think there is a lot of inherent value in freedom of expression and the right to voice your opinions and have your own beliefs - even if other people think they're wrong/abhorrent/etc, and on a more practical/selfish note I think that freedom is important for progressive views (i.e. views I agree with!) to have the room to grow and fight for what they believe is right. If it's okay to silence far-right points of view, whose to say the same wont soon be applied to far left views, or any other views that whoever makes the rules disagrees with?
In short...
I do not agree with what you have to say, but I'll defend to the death your right to say it.
So, I think it's wrong to sack somebody because of their beliefs. Full stop. Even if I think those beliefs are awful. (As long as they don't affect somebodies work, i.e. they're not being discriminatory within their job, giving inappropriate advice to people in their care, using their job as a platform for their personal politics, bullings/mistreating fellow members of staff/customers, etc...).