Just saw that documentary about Janitors stating Peter Dinklage.
The film is, at its core, about the erasure of invisible labor. A man whose name is never spoken on camera, whose body is disposed of like the waste he handled, whose only tool is a mop.
The mutation, the green skin, the mop-wielding violence, that's subtext. It's the film's way of saying: this is what happens when a janitor is finally seen. The corporate villain, the band, the hostage rescue, the serum, all of it is just the set dressing of a workplace where the person on the floor is the only one who actually keeps things running, and the company's answer to that is a waste pit.
(Just kidding, it's a hilarious gorefest)