Hendricks did get beat by Rick Story Clyde. I think people just view him as another hyped 'contender' for GSP's throne. He is simply filling in space until Rory takes over after GSP retires. That's why everybody has him in their 'whatever' category!
Everyone has bad fights, look at GSP vs Shields. Anyone with wins over Fitch, Kos, Kampman and Condit is a legit contender, it isn't hype. Will he win? Hell who knows, but I wouldn't consider the wave behind him one built by the UFC machine. In fact he may be the one fighter the UFC kept pushing off and he kept proving them wrong.
Also I am not as sold on Rory as I previously was. I do think he could very well in the future take over the division, but I wouldn't be surprised if he ran into a few more bumps before getting there.