[T]here are cultural and technical sources of performance issues [in scripting/dynamic languages], and they are related. In his talk, Alex criticizes the naïveté of both tools and programmers. He bemoans the lack of sophistication in tools that make implicit hash addiction and allocation problems unavoidable, but he also complains about the commonality of poorly performing idioms in scripting language code. The tools, or in some cases lack of tools, encourage these poorly performing idioms in this code.
There is a change coming in the languages we use for common tasks. The tradeoffs we made when we all chose dynamic languages a decade ago (perl, python, ruby, etc) are starting to irk us because they’re not longer tradeoffs we have to make. The next generation of languages (Go is the topic of the linked-to post, but I suspect Rust will be on the list) is allowing us the rapid development without the performance tradeoffs.