I was addressing your mobile / web vs. native angle. In those markets, in my opinion many of the products, having to choose between being done right or not being done at all would do better if they chose the second option.

I don't have anything against Python per se. Sure, it isn't the fastest language out there (even considering the high-level features it provides), but rarely the problem with application performance lies squarely with Python. It's more often about not putting time to "make it good" and "make it fast" after "making it work". Especially with - from what I hear, quite good - FFI capabilities of Python, in the worst case one could always push the most intensive computations down to C.