I really don't understand why you would say this, it's obviously false. Setting aside the subtler point of what it means to "have" something in mathematics: c

I really don't understand why you would say this, it's obviously false. Setting aside the subtler point of what it means to "have" something in mathematics: clearly only some vector spaces even have the potential to introduce an inner product. Consider F for some random finite field. You can make a vector space from it, but what would the inner product be? Or R x F for that matter, you could never give that an inner product. That's why the concepts of "vector space" and "inner product space" are separate concepts. Some vector spaces aren't, and could never be, inner product spaces.