It's more of a cost benefit analysis as the author pointed out. When so much of valuable content is surfacing in hackernews and other streams, it's not cheap, rather a wise decision not to spend money.
I got tired of the these I like to use and the people I like to read disappearing. Now I just pay a few bucks a month for everything, and things just stopped disappearing. I don't have to worry about switching apps or finding new people read, which I would have pay with time instead of money.