> scripting language frequently is the performance bottleneck

I'm not sure I'd use the word "frequently" here, but I could just have a different experience. Most projects are boring CRUD stuff, and something else have always been the bottleneck before the actual language itself, most of the times different types of I/O but also just poor choice of algorithms/data structures. I don't think I've ever actually came across a situation where the language itself was the bottleneck of the performance, but I don't normally work super close to performance-sensitive projects as I said, mostly common web tasks.