Why is mace illegal in Wisconsin?

If we're about to pass a concealed carry law in WI, does that mean I can have mace? Or does that mean that a person can threaten me with their concealed gun and I won't be able to defend myself? I know I'm defensive here, but it seems unfair that people can carry guns and knives but I can't defend myself with a keychain of spray. If anyone can provide me with the rationale, I'd appreciate it.