Couple of issues I have with this article

1 - This decisions seems based more on the fact that Rails isn't as trendy as it used to be

2 - Some of these benchmarks for performance are pitting interpreted languages against compiled languages which will explain some of the performance difference

3 - Saying that Rails is static makes me think that the author would prefer a NodeJS like situation where every release might contain backwards-incompatible changes

4 - You don't future proof your application by trying to predict what will be popular in the future, you future proof by investing in stable technology and ensuring you have the talent pool to maintain it