We were wrong. We aknowledged it and improved. It's a good thing.

Have you considered that maybe the language had not evolved enough for them to be appealing. With b'' and u'' string syntax coming into the language, there is a realisation that string interpolation can be an opt-in feature among other reasons.

What you have is decision making analogous to the function

    evaluate(string_interpolation, python_ecosystem)

which is different from

    evaluate(string_interpolation)

> With b'' and u'' string syntax coming into the language, there is a realisation that string interpolation can be an opt-in feature among other reasons.

This argument won't fly. Did you know that string interpolation in Perl and shell was always an opt-in feature? And despite that it was frowned upon by Python community.