> Similarly anyone could pick up a broom and sweep the job floor, but without clear delineation that is ONLY the janitors job then why not make the electricians sweep the floors when they're walking back?

They are not being forced to sweep the floors, sometimes people are choosing to step slightly outside of their role to do something when it is more efficient for them to do it rather than inefficiently finding and having someone else do it.

If I make a small mess, I can:

1. stop working, contact the janitor, and ask them to clean it up, or

2. grab a broom, take 2 minutes and clean it up, and continue working

In most cases 2 is the better option, and most good workers would prefer to just do 2.