It's fast and simple but not a good heuristic. It's like judging a car by how expensive it is. It has nothing to do with how the thing performs.

Optimising for size is such a waste of time in this day and age. I know I would rather choose a 5 MB statically linked binary than a 5 KB dynamically linked one, because they take pretty much the same amount of perceived time to transfer over the internet, yet the smaller file might take more of my time because I need to find and install missing dependencies.

On the list of priorities for language developers, size optimisation is towards the bottom, unless we're talking about embedded but we aren't.