For an author of an Open Source project to say it's "not socially acceptable" to use their software to make money without contributing back is heavily idealisti

For an author of an Open Source project to say it's "not socially acceptable" to use their software to make money without contributing back is heavily idealistic, but we don't live in a meritocracy. If I use the software and make money, but don't donate, should I fear being socially reprimanded? What's the line there? Piracy is one thing, but this borders on extortion and frankly would make me uncomfortable using this software.