You only have to read the HTML source if your browser doesn't show you the feed button next to the address bar. That was kind of the author's point.
In fact, I'd bet that part of the reason many people don't use the address bar feed button is because the practice of having links to feeds is so common, and anything on the page is automatically more obvious than something out in the browser chrome.
In fact, I'd bet that part of the reason many people don't use the address bar feed button is because the practice of having links to feeds is so common, and anything on the page is automatically more obvious than something out in the browser chrome.