What do you expect? Getting more modules, new vapor and wing flex effects, updated aircraft models or a new graphics engine without increased hardware requirements? Same with FSX, a standard install doesn't require that much space. But if you want high fidelity aircraft, photo-realistic ground textures and high quality airports, you're gonna have to pay with additional space on the hard drive and an increased load on CPU / GPU. It's your choice to do so and it's not gonna come out of thin air...
And as mentioned above, most of the files in an update replace others, they're not new.