As far as I'm aware, none of the statues being defaced had anythign to do with Apartheid at all...
Granted, to us, however to the masses anything relating to before 1994 is classed as racist / colonialist and apartheid related. So then before it is obliterated forever perhaps it should be collected and moved to more appropriate locations, so that the history can be remembered so it can not be repeated. Call it what you will "The long walk to freedom Memorial Park" or Piet Snot's History Spot, as long as it is preserved and presented in the correct context.
If it eases their frustrations, then perhaps they can move on to actually building a nation, instead of trying to destroy one.