What is it with WD-40?

Each product has its use. I use WD40 where hinges or slides need lubed to stop rust from forming and it works great. We use it at work on all the door hinges at every service and they never rust. I did use PB Blaster to free rust but have now switched to Deep Creep and the guys at work even switched because it is at least twice as good at freeing rust.