Yeah, it depends on what you're trying to accomplish with the language. The most interesting new languages I've seen lately have focused a lot on performance (Rust, Julia, Nimrod, etc.) but the author of the linked article is more interested in how different languages can be composed together, so for him performance matters only inasmuch as the language is useable.

My main point though was that part of Julia's high performance is due to specific decisions by the language designers (e.g. the compiler knows a lot of information about types even though the programmer can mostly ignore them), while a language like Python wasn't designed for performance and is thus harder to optimize.