Why is a niqab not allowed in Hajj but allowed in daily life?

To the reader of the question, I have been thinking of wearing a niqab but the disallowance of the niqab by the Prophet Muhammad (S.W.) during Ihram at Hajj, is creating inconsistency with the choice of my wearing the face veil. Can you please provide me a solid answer in regard to the question given? Thank you!