I concede that my opinion is worth very little to nothing and I didn't even check what's the mathematical consensus on this matter, but when one sees that 1100, 110, 30, 22, 20, 15, 14, 13, 12, 11, 10, A are all the same number one starts thinking about the difference between symbols as numbers and symbols as digit.
I hopefully didn't make mistakes in the several representations of twelve.