So if you are saying that every single person who displays a confederate flag is a racist nazi

Of course I'm not saying that, tho some assuredly are. The vast majority are in all probability simply ignorant of the real history of the Battle Flag (and what it symbolizes especially to Black folks) just as they are of the real causes and history of the Civil War (which was sloughed off for years in U.S. schools as a simple disagreement over "States' Rights")and Reconstruction. So at least, in part, its a matter of education, as you & Kevin have suggested. And of simple respect for the Black segment of the U.S. population.

...which is surely not the same with the said flag in the States?

Certainly not. It is in no way "illegal", & despite what the NRA-like crazies are ranting about, no jack-booted government thugs are going to confiscate all the Confederate flags - Its about not flying them on government property or giving them - or seeming to give them- official government sanction.

And not before time.