And my point, which you cutoff early, is that with Python you can have both.

Yes, you can have everything in every language. After all it's turtles all the way down.

What makes us successful as software engineers, in the end (and IMHO), is the efficiency level at which we reach our goals. To my eyes, when deliverability is the goal, then a language where native (cross)compilation is first class citizen is the most efficient path. But don't get me wrong, Python is really great and still a good choice for that scenario (I'm thinking of dropbox, for ex).

But setting up a build system is a tiny part of time it takes to finish a project, so why would it be a major factor when choosing a language?

Mainly because I currently work on long term projects, building entreprise grading systems. Here you want simple, dumb technologies for which you'll still be able to put up build OS in the years to go.