Oh Pur-lease...

Why do some people think that they are a God and that their opinions are so highly more significant than the rest of us mortal beings?
My grandad has just gone through the long process it takes to seriously annoy me in a matter of five minutes. While I love him to bits his bigoted opinions put across like they are fact that all of mankind must adhere to never fail to frustrate me.
For example, he seems to think it is justified to claim that people from Scotland are scum.
Or to say that all asylum seekers should be hanged
Or to use the n word which I can't even type let alone say in casual referal to a black person.
He also sees fit to criticise parents at every turn on how they bring up kids, yet he has had no kids of his own (he is my grandad purely because he's with my granny. I never knew my real grandad)
Now my granda may sound an ogre from this but really he isn't...his heart is in the right place he just isn't wise.
The thing which enrages me is that he thinks he is.
And people who never accept when they are wrong or even listen to an opposing argument are, in my opinion, impossible to hold a conversation with.
My grandad, rather annoylingly, is in the mood tonight which sees his fit into that category.
I'm staying well out of the way