Hazrat Moulana Ashraf Ali Thanwi (rahmatullahi ‘alaih) once mentioned:

How strange it is that people don’t look down upon a trader when he trades, yet they look down upon a worker who is engaged in his employment. Logic and justice both demand that if we do not look down upon the trader, we should similarly not look down upon the worker. The only difference between both of them is that the trader provides his merchandise while the worker provides his services. When they are both, in essence, doing the same thing, then why do we look down upon the worker? (Malfoozaat Hakeemul Ummat 6/173)

Source: Ihyaauddeen.co.za