It's a normal scenario for display units in retail stores as well, which store video and audio files to show off the device's features to consumers, and was the reason for the confusion regarding the Galaxy S5 as well. In fact, Samsung has reduced the amount of storage its software takes up, with the Galaxy S5 offering 10.7GB of storage for user files such as apps and media, which could go even higher when the company is done optimizing everything on the final version on the phone. Granted, this is still quite a bit lower than the available storage on devices like the Nexus phones, but it's ultimately a trade-off that has to be made for some of the useful features that Samsung offers on its devices.
When you factor in the availability of a microSD slot and the option to move apps to the external storage on Samsung devices, an option not available on the stock version of Android, it's pretty easy to see that the Galaxy S5 won't be presenting any issues related to the available internal storage space.
