First of all. No one is proposing that you should not be able to buy, possess, and display the flag of treason but some retailerrs have voluntarily bowed to public pressure, not the government, and stopped selling the damned thing.
Second of all William Porcher Miles, the designer of the stars and bars, said that secession was necessary to uphold the "honor of a slaveholding people" and that slavery was a "Divine institution".
And here's a tidbit from the Texas declaration of Secession.
"In all the non-slave-holding States, in violation of that good faith and comity which should exist between entirely distinct nations, the people have formed themselves into a great sectional party, now strong enough in numbers to control the affairs of each of those States, based upon an unnatural feeling of hostility to these Southern States and their beneficent and patriarchal system of African slavery, proclaiming the debasing doctrine of equality of all men, irrespective of race or color a doctrine at war with nature, in opposition to the experience of mankind, and in violation of the plainest revelations of Divine Law. They demand the abolition of negro slavery throughout the confederacy, the recognition of political equality between the white and negro races, and avow their determination to press on their crusade against us, so long as a negro slave remains in these States
We hold as undeniable truths that the governments of the various States, and of the confederacy itself, were established exclusively by the white race, for themselves and their posterity; that the African race had no agency in their establishment; that they were rightfully held and regarded as an inferior and dependent race, and in that condition only could their existence in this country be rendered beneficial or tolerable."
