Agreed. The GNU Guix project (of which I am one of the developers) sees reproducibility as a means to an end: empowering users with verifiable, trustable software that they can control. Thus, reproducible builds on a proprietary system, while better than non-reproducible builds on a proprietary system, don't accomplish very much for user freedom.

https://www.gnu.org/software/guix/news/reproducible-builds-a...