It depends on the article. Yes, there are some articles I would gladly pay $15 for (like Boneh/Shaw's work on collusion secure fingerprinting). However, in a lot of cases, I'm going to read a paper for its citations. If I have to pay $15 for that paper, and then pay over and over again for each additional paper that I want, the costs quickly become unsustainable.
Though, as the replies to my question (http://news.ycombinator.com/item?id=2133193) point out, many times you can get a paper that you need by contacting one of the authors, so it the payment isn't as big of an issue as it could be.
Though, as the replies to my question (http://news.ycombinator.com/item?id=2133193) point out, many times you can get a paper that you need by contacting one of the authors, so it the payment isn't as big of an issue as it could be.