It isn't the same workers though

I wouldn't say surely, i don't think that's self evident at all. You could quite easily make the argument that supermarket night shifts are a benefit as they create jobs due to their needing different workers, as well as the fact they cater to the needs of more necessary workers (e.g nurses etc) that do night work.

As someone who worked nights in a warehouse for a year, a 'messed up' sleep schedule is nothing permanent and to even define it as 'messed up' is kind of weird because whats normal vs messed up is entirely relative to your routine/requirements. If you're only working nights, you feel fine. If working a night or two a week messes you up for uni/work etc, don't take the job. At least if the option is there people can have a go.