Personally i dont see what the problem is.
Ok his pricing structure is not what it could be,but as far as working two jobs...well lots of people do it if they need to make ends meet.
You dont know his circumstances,he may have a family at home and cant support them properly on just his post office salary so goes out and does a bit of wc to supplement it,good luck i say to him.
You see everyone presumes that because you have insurance (which is not a legal requirement...so anyone without it is not doing anything wrong) and are registered (registered as what?
?) that you are entitled to have the upper hand over others doing cleaning.
He may also be a postman who aspires to be a wc,and has set up a part time round in readiness to quit the post office when his round is built up further....