> How is this different from proprietary software?
Most free software is proprietary software! Big chunks of Facebook's code base is proprietary, and the data they collect is extremely proprietary. Ditto for google.
By "the expectation that software should be free", parent meant the expectation that you don't pay money for access to a hosted copy.
How is this different from proprietary software? Where you have no idea what's going on under the hood?
Granted, "giving in order to get" is a common and effective social engineering tactic.