WHAT?!! Are you freaking kidding me?! Ok, Hinata is the most underdeveloped of the K11? Yeah. Ok. Show me something from Tenten's past. Or Shino's. Or even Sakura's. You can't. Because they have been given little to NO backstory, while Hinata is a fully fleshed out character, where we've seen a lot of her past, where her love for Naruto originated, the struggles she's faced in her life growing up in constantly being picked on, put down, and abused by family and classmates alike. Her love for Naruto is, of the K11 relationships, is the best. She's been there for Naruto and supported him and Naruto has done the same. Hinata nearly was killed by Pain trying to save Naruto's life all out of love for him. I didn't see Sakura going down there and doing that. Hinata is brave when she needs to be, has grown as the story advanced, and isn't the shy little girl she used to be, at least not to the same extent. She's more confident after proclaiming her love for Naruto, uses her love for him as motivation to keep fighting in the war against impossible odds, and it can be aruged that she even managed to save Neji during the war.
To say Hinata has no character development or call her a cookie cutter character is arrogant and misguided. She's been given more backstory than the K11 (not including Naruto). Oh, and by the way, character bashing is illegal on this site, so you're going to get reported and most likely banned. Congrats.