They're smart alright, but I think Julia has gotten a lot of play on other channels besides the Matlab/tech world. The stopper is for me is use cases. I play with ideas in Mathematica (notebook IDE for decades) because it has everything at my fingertips, keep J programming language opened on my desktop for quick prototypes (not just as a desk calculator), and if I need technical libraries and speed, I just use C with the relative libraries (even though I should learn Fortran :) ) I like Julia's syntax, and I think it will be more general purpose as it matures, but it is already the wild mistress of the Matlab playboy.