There's a reason it's like that... it encourages you to keep your files in "your" section of the laptop - your Profile, which includes "Documents". There they're out of harm's way, and since you know where they all are, it makes backing them up easier. How are you going to back up documents stored in the root of C: - select them individually, every time?
As a rule, you should only have Administrator privileges when you need to do Administrator-type things. It's far to easy to make a "little mistake" that screws up the system. For normal use, you should be a normal user. This is a long-running UNIX practice that Microsoft is only now enforcing, kinda, so I actually agree with you being locked out of the root of C:
