It means the ecosystem for Docker is more robust than for a Nix, which is patently true (see my comment here: https://news.ycombinator.com/item?id=26689378). I want to like Nix (and indeed I use it for some things), but it’s wildly immature, and maturity is a fine reason to choose one tool over another.

Also “imagine thinking...” is just vapid snark. If you must snark, at least make it substantial.