They are typographically the right thing to have been using all along.

Using ' and " to pretend to be ‘/’ or “/” is on par with the typewriter days where people would use the l key to stand in for 1 also. A justifiable approximation when technology limitations prevented using the real deal, but an approximation all the same.

As others have commented, for the same reason that we use smart parentheses instead of the more utilitarian |.