But if those system were developed in another language, maybe by the time they were released there would not be any market demand for it anymore. I've seen it

But if those system were developed in another language, maybe by the time they were released there would not be any market demand for it anymore. I've seen it happen where everything is meticulously performance optimized in C and by the time it is released it is fast, snappy, scalable but by then the market has moved on and nobody wants to use it anymore. Often "We moved from X to Y because X is slow" is seen as a failure of X, but it is not. It could mean the feature was deployed quickly, caught on and has customers which want to use it. So it can be a testament of how productive X is.