It's a good idea, IMO. He has a place in history, but not a place of honor that deserves a monument.
Seems like he was a slave trader, a war criminal, and a klansman. Why should any city, but especially one that's 60%+ African American, keep a monument to him and pay to maintain it with their taxes? Just because he was a general in rebel army that fought to keep their ancestors enslaved?
It's not his original place of burial anyways, so he should be relocated to a private cemetery, and if a private society wants to house the monument to him, that's fine by me. But to impose it on the people of Memphis is what's really nuts.