Sarchar: That can be added easily. You could simply rent out storage space.
To whom? Who's responsible for fulfilling the payments? How do you fairly get paid for that storage?
Your node offers storage space for a price. Clients pay. You store the files. You can integrate proof of storage and more and use Bitcoin's scripts to make sure neither side is at a significant risk of getting screwed over. It's not like it can't mimic most of the features of Bitstorage.