People who say stuff like this must not have worked on enough Linux environments. Bash scripts aren't fully portable, and there are absolutely differences in environments which prevent portability of bash scripts. Since using Nix, I've realized the number of bash scripts which are only superficially portable are drastically higher than the number which are actually portable. As one trivial example, how many bash scripts use the more portable shebang of `#!/usr/bin/env bash`? Extremely few. And every one which hard codes `#!/bin/bash` has created a less portable script most likely without ever having realized it. Guess they are all muppets though right?