I think people look ahead. They see how the app evolves (from A to B) and then claim "X not good". Where as they do not judge the flexibility of X as a tool to

I think people look ahead. They see how the app evolves (from A to B) and then claim "X not good". Where as they do not judge the flexibility of X as a tool to move from A to B. Typically they look at B and make claims from that perspective. Those companies that succeed in python usually have a long path and python was never successfully removed and most likely attempts were made. The PL economics is often stickyness and its not easy to propose absolute measure.