be not in the business of (doing something)
To be one who typically does not do a certain thing. I'm not usually in the business of offering financial advice, but I would suggest splitting the investment across a few different companies. Look, I'm not in the business of talking behind other people's backs, so go gossip somewhere else.
not be in the business of doing something
not intending to do something (which it would be surprising for you to do): I’m not in the business of getting other people to do my work for me.