Maybe that should be more narrowly read as “Twitter users will never pay” or “Facebook users will never pay” which is probably true because the simple reality is that these services offer low-value content that is cheap to produce and easy to consume. It’s not valuable so readers won’t pay.
Consumers do pay for valuable content like Netflix, New York Times, books, etc., because they actually take effort to produce and are thus actually valuable. Twitter and Facebook and much of the free Web is dreck that is not worth paying for.
Yes, sorry Social Media readers will not pay, because as you say the content they are consuming is mostly snippets of thought and links elsewhere, it's not the sort of service you'd subscribe to, but it is the sort of service lots of people like to use.
I do think there is a segment of users who would pay though - those who use the platform to broadcast and want to have a bit more control over their feeds/profile/comments.
Consumers do pay for valuable content like Netflix, New York Times, books, etc., because they actually take effort to produce and are thus actually valuable. Twitter and Facebook and much of the free Web is dreck that is not worth paying for.