Whatever happened to that privilege that was endowed on us? In case you're arguing that 'nobody's hindering you from expressing yourself' -think again. Our society has limited our tongues from releasing certain extents of language and insights due to cultural, political, moral and religious reasons. If we must say something against them, we must say it deep underground.
They say that 'we must think before we speak/act.", and true enough, it is necessary to follow suit to avoid miscommunications and squabbles. However, I don't think that any person must be ceased from expressing a well-thought speech because the listener refuses to be affected by the sentiments of the speaker. If there's one thing we must learn to do, that is to have control over our emotions as a listener. To zip our lips; open our ears; and, if you must, harden your heart and stable your mind for if there's one peeve speakers have, it is a listener who manipulates the orator's discourse.
So as much as one person's statements are against your will and beliefs, you have to pay him/her the respect that he/she deserves. Let them speak.