The actions by the SC government are great, if long overdue.
I can understand honoring ancestors. I can even understand honoring them as people, even if they fought for absolutely the wrong cause. But then why honor them by using a symbol of the hateful cause for which they fought? Why not use a more appropriate symbol for them if your purpose is "heritage" and not "hate"? I am certain there must be many symbols of personal courage, of patriotism that can be used instead and that don't symbolize treason and slavery.
There are a lot of hypothetical ways that other people might answer the question. I don't know if there is any symbol, though, that could be connected with their service, but could not be connected with treason and slavery. That was kind of the point of their service.
As an aside, treason and slavery have a pretty strong role in American history, not just in the South. The Union army had an awful lot of pro-slavery folks in it. To say they were fighting against slavery just doesn't hold up. The American economy, not just the Southern economy, was very much built around slavery. Slavery was a dying institution, but it was far from dead in 1860.
My own answer is, "Why not?" Ok, fine, they fought in a lousy cause, but it was their cause. They are historical figures. We have battlefields. Battlefields are where two armies met. One of them was from the South and had a certain symbol. In souvenir shops at a battlefield, it seems to me to make sense to offer souvenirs representing the people who fought on that battlefield, and the symbols they used when fighting seem to fit pretty well with that. Maybe that guy buying coasters wants to celebrate racism every time he opens up a Pabst Blue Ribbon. Maybe that guy wants to use them as archery targets. Maybe.....who cares? They are coasters.
However, some people oppose such things. Those things were associated with slavery, dammit, and SLAVERY IS WRONG! They courageously take on the pro-slavery forces, one coaster at a time. Yes, it is just a coaster, but it is an evil coaster! "IN MY HOUSE, THAT FLAG WILL NOT COAST!"
Ummm...yeah. Very noble.
And now, in Congress, you have people saying that gravestones cannot be marked in the traditional way, with the flag under which the soldier fought. Well, whatever. It all looks like political grandstanding and posturing to me. It's an opportunity for people to take a meaningless stand and pretend it's something important. Some old lady goes out and marks her ancient forebears' graves with Confederate Battle Flags because, who knows why, but her dad did it, too. Well, not anymore! That is an outrage up with which we shall not put!
ETA: And, just in case anyone has forgotten, I, too, think it makes no sense to fly that particular flag in that particular place in South Carolina.