[everlastinge]

So refraining from calling non-Muslims kuffar takes you out of the fold (a theological position), but committing major sins doesn't take you out of the fold; so refraining from calling non-Muslims kuffar is worst than major sins... What atrocious reasoning.

You seem to have a seriously poor understanding of the post. One is an unbeliever because he deems an other religion besides Islam as VALID. This is a part of belief like believing in the fire and heaven.

Your reasoning would be better if you compared it to those who deem a major sin halal. They are unbelievers too.