As humans we are forever evolving, how we gather information is no exception. With so much information now available at the tap of a few keys and buttons (or screens). It's no surprise that we have developed new skills for quickly determining if a website contains what we need.
Headings are not the only factor involved of course, people consider page load time, good graphics, design and layout also (to name a few). But in the search for information headings are the signposts most people follow.