I think it is a ridiculous overreaction which bans a renewable resource which could be sold for the benefit of species.
Elephants don't live forever and when they die naturally this is a resource African countries could use to protect wildlife. What is needed is more anti poaching measures. Countries like South Africa and Zimbabwe and Botswana have greatly expanding populations. What are these countries doing that those with falling populations are not.
Countries having the ability to earn an income from tusks gives better incentives for conservation than making them worthless. The problem is some governments wont spent the required amount on enforcement of current laws to control poaching.
Banning all ivory will make no difference, it is already illegal to poach and export this ivory, how will making it more illegal help.