I think the idea is that you can move the threshold on when to implement in Fortran/C(++) since you only have a '1x-5x slowdown' for most common application com

I think the idea is that you can move the threshold on when to implement in Fortran/C(++) since you only have a '1x-5x slowdown' for most common application compare to the 20x-5000x slowdown with R/Python/Matlab/..