Nope, the background check should apply only when buying from some one who does not know the buyer personally.
Such as if I walk into a gun store to buy a gun, they should
be required to check me out.
If my brother-in-law wants to sell me a Glock, he knows me personally and he is taking the responsibility for the sale to a non-criminal. Therefor I agree with you no check is required.
That is Not what the poll was about. When they say 'All' they mean all. Do you really believe legislation could/would be written in such a manner you described?
Remember, there is no such thing as Spirit Of The Law...only the Letter Of The Law.