Why are thrillers still so popular?

Thrillers started with the godfather of the thriller Alfred Hitchcock, his films we're insanely popular in the 1940s, 50s and 60s. this is because they had the power to grip the viewer to the point that they become enthralled in the character and there story. Sadly as the movie industry developed Hitchcock's films we're left behind. That leaves the question as to why Thriller is still so big? The thriller genre upped it's game using the new technology to keep audiences on the back of there seats with more action, for example The Bourne saga and the recent James Bond film Skyfall. More action isn't the only way the thriller genre has stayed fresh, psychological thrillers have become a huge part of cinema scaring, distressing and at times disgusting the audiences who shoe up to watch films such as 'fight club', 'blood diamond' and the 'girl with the dragon tatoo'.