Because there is absolutely no reason too? Do we still have pre colonial statues of British viceroy's or governors? We don't because we no longer are affiliated with the British. Same here, we no longer are affiliated with the Confederacy. It has been defeated for for nearly 160 years. If people want to commemorate Confederates, go ahead, but the government has no obligation into honoring the enemy.
Like I have stated before, the men who fought and died on the Confederate side were fighting for their country just as much those from the Union side were. Even if you think Confederates had a false premise, this is what they believed and didn't see it the way those who opposed the Confederacy do.
Tajshar2k The Confederacy was not the enemy to the southerners and there are monuments that commemorate the honor of the Confederate soldier and also in the south there are monuments that commemorate the Union soldier. So if you want the confederate monuments taken down the we should take all United States monuments down.