Can anyone give examples where "keinerlei" is better than "keine"? Is "keinerlei" more emphatic?
Furniture is a collection of different things: chairs, tables, closets etc. If you want to say "some furniture" you could say "allerlei Möbel" meaning all kinds of furniture. "Keinerlei" is the opposite of that, no kinds of furniture or just no furniture.
I think both would be correct to use, if I am not mistaken, but to me "keinerlei" sounds stronger or more extreme: I would use "keine" for "no" or "none" and "keinerlei" for "none at all". Hope that helps a bit.
Seems to me like "keinerlei" is supposedly more emphatic in a way. I translated this sentence as "Why do you have no furniture whatsoever" and it was accepted. I like Lenkvist's explanation too though.
keinerlei is "none at all". As we would expect you to have some furniture it an accepted and IMO a better question is "Why don't you have any furniture at all?"
Spot on. And as in English it's a mass noun so (in normal usage) you don't have two Furnitures but twice as much. It come from the same root as "mobile" implying things you can move around unlike the walls floors etc. "Immobilien" is the word used for housing and real estate.