The problem is knowing upfront which of your work would need to be reproducible, or having the discipline to do all your hacking starting from such reproducible setups.
Do you know much about how reproducibility is approached in Julia? Maybe hold off on calling it a lie if you're not experienced in what you're talking about.
Scientific reproducibility requires only that versioned binaries be functionally equivalent if they have the same version, which is quite independent of this and certainly exists in Julia.
Would love a link to the Guix mailing list discussion, if you can dig it up.
About two hours is the cumulative time one must cater to the Dockerfile for a 3 weeks project.
But it requires institution insisting on reproducibility, and fostering best practices to make it even easier for the researchers to be compliant.
I get it that reproducibility can be quite hard for biology. But ML cannot be taken as an example of a hard problem.