They may be "expensive chariots" but they have more close combat power (minus impact hits), more survivability, and free reform (w/musician). And though it's true 0+ saves are gone you can still get a 1+
Calling them expensive chariots would be more appropriate if we had access to chariots in the army. Seeing as we don't have a chariot in the army book, finding a way to use something in a comparable way is still useful. Perhaps there are better ways to use points or COC, but that doesn't necessarily mean that fielding them in small groups is out.