> Also no real-life product or business is built using a single PL I've worked on many "real-life" products where that was exactly the case. And plenty where t

> Also no real-life product or business is built using a single PL I've worked on many "real-life" products where that was exactly the case. And plenty where the only second language was for the script for running the build. I certainly agree choice of PL is only one of many factors that contribute towards success of a software company, but it's still an important one. Choosing a language that makes it impossible to find good devs who want to work for you is almost a guaranteed death sentence.