I mean, if Disqus or facebook had been offering these as paid services, would we expect them to be respectful of privacy? When buy an android phone, amazon echo or whatnot... When we order stuff on amazon, subscribe to Spotify, download a paid app or even purchase a car... do these come with the expectation of privacy?
Increasingly, data gathering is just built into everything, free, paid or foisted. I think the "if you aren't paying, you're the product" trope is trite at this point. We're "the product" regardless.
Framing this in terms of "the problem with free" is off, IMO. It doesn't point to a solution. A paid facebook or google is neither realistic nor likely to solve anything. All it does is point the finger in the wrong direction, as if we, the ignorant masses, are selling ourselves willingly.
Corporate (and state) espionage is simply the default. Avoiding it takes effort, and compromise. Part of that compromise may be financial, or it may not be.