Not every post is for everyone. (And like Rachel said, not reading an article has not typically prevented people from entering a discussion and I don't think it ever will. That's often perfectly fine, someone can offer insight in response to what people are saying in the comments.) Imagine an interesting, long form article written by an independent writer whose livelihood depends on subscriptions. So not a news story with many alternatives, in other words. Why shouldn't someone link to it, and say "here's a great article, I recommend subscribing to this writer?"