"We have included our in-house Java web framework, Gemini, in our tests. ... "
Then you see results for some languages that are completely out of whack with most other such benchmarks (they themselves mention the weirdness of Sinatra vs. Rails, for example).
Then you see on a couple platforms that more performant mainstream options have been excluded, for no good reason.
Then if you look at the repo, there are deployment choices and code mistakes in some of the other languages which go well beyond elementary incompetence...