Well in a way it makes sense. Its like learning any other technology stack. The core stack may not be the best fit, but its considered a better bet to hire some

Well in a way it makes sense. Its like learning any other technology stack. The core stack may not be the best fit, but its considered a better bet to hire someone with experience in the target language/stack because the learning curve is reduced. AKA, a developer that knows the same framework your app uses, only has to learn about your specific application rather than all the background libraries/etc your using. Its the same reason for preferring a C programmer for a C position over a ruby programmer (or flip it). Sure the ruby programmer might be awesome and after a couple years more productive, but in the meantime they will be making a bunch of newbie C mistakes, and generally bootstrapping slower. This is part of the reason i'm in favor of generally reducing the number of languages/frameworks in general use. Its better for everyone if we all agree on some simple baselines even if they may not be the most optimum for any given problem. The efficiencies of repeatedly avoiding a bunch of rookie mistakes (and then having to debug/fix/test them for the next few years) is well worth it in the long run.