No problems. There are enough dimensions involved in what makes a language good that Im pretty sure I could rationalize why any language is better than another, measured along only one of them.

Robustness. Speed. Simplicity. Easiness. Conciseness. Writability. Readability.

Hard to tell which are independent vs correlated, let alone how they factor into productivity. And productivity is also a function of the kind of problem you work on.