You nailed it. It's in Google's interest to provide the best user experience and a large part of that is optimizing for the "best" result. Whether or not a user returns to search results, or executes a subsequent search are some of the many signals used to determine this.
It's a great metric for a lot of things, but definitively not to determine the value of a piece of journalistic writing.
Here we're saying that the article SHOULD be free in order to gain value. So basically we're saying: it's ok to attribute no value to it if Google thinks so.
I'm not a fan of hard paywalls, but this is definitively a fallacy in the definition of value, and Google shouldn't have it so easy.
Google isn't determining the value of paywalled articles, the general population is. Google is just facilitating the desires of users. The obstructive thing for Google to do would be to put WSJ near the top because Google thinks it's valuable, even though the users find it useless.
