Garp has glory but Whitebeard definitely does not. To me being called a monster and a demon is not any kind of glory. Being world-know and have glory are two different things. Don't forget that pirates are hated all over the world, even some legendary pirates. Indeed, Marco said to Ace that the Whitebeard Pirates were all hated by the world and that's why Whitebeard calling them their sons made them happy.
And Garp is not really free unlike you said. Garp can do anything he wants AS LONG as the Marine accepts and bears it, as long it does not go against his duty. Do you remember what happened to Garp at Marineford, with Ace and also somehow with Luffy. Garp's feelings were hurt and he could not do anything to protect his family because he was a Marine. If Luffy said that the Pirate King is the guy with the most freedom in this world, there's a reason. If both Ace and Luffy refused to be Marines, it's because being a Marine means you must follow your duty no matter what happens, and that's against their vision of what freedom truly is. Being a pirate is as Whitebeard said the right to choose what to believe in, whereas being a marine means follow the organization's orders and policies. That's the reason there is a hierarchy in the army.
