ANSWER:

You are helping them in their work where if no one worked in such a position, their work wouldn’t be complete! 

By your logic working as a receptionist at a brothel or a bar is perfectly fine!

Why is it that working in a non-Islamic bank is prohibited even when one’s job does not at all, in any way whatsoever, involved or help the bank in their practices of riba? How can things like giving/taking people cash or exchaning currency be prohibited?