Imo profit without compensation is exploitation. If you are paid a salary and the owner sells your burger for more, that's profit. If you make a burger and the owner sells it for profit without paying you anything, that's exploitation.
As I just found out, as bizarre as it seems, the definition of OpenSource requires that your work can be exploited by large corporations.
The Lemmy users in the thread were angry with a developer because he didn't want his program exploited by Google/Microsoft/whomever.