While what you say is true, there is still a huge gap between the performance of javascript (and even Ruby) and that of Python. The efforts to optimize Python are lagging behind, so there is a lot of things that still can be made faster.
Instead we got parentheses around print.
I think what always ends up failing here is that, as others have stated, they won't make breaking API changes, in particular those in charge of driving Python forward are extremely hesitant to break the C API for fear of losing packages that have make Python so popular.
I would imagine, if the leadership was willing to put in the elbow grease to help those key packages along the changes when they happen, they could do it, but I understand that its not always that simple