Don't tell me that cloud is nothing new - I've heard it all before

I'm starting to get a little fed up with all the cloud haters. You know the ones, they hear someone mention 'cloud' and either start ranting about how insecure it is, how pointless it is or worse yet how it's not even a new technology. Yep, the loudest and most annoying cloud haters are the techno-pedants insistent on proving that the cloud was invented decades ago and what we have now is nothing more than a marketing exercise in rebranding existing technology. So, what exactly is the cloud then?