This happens because product managers, developers, designers, ect, like to get creative. They think that they need to invent something new; AND, we (in the industry) see how a certain group of users is constantly confused by the files and folders concept.
Usually, cooler heads prevail and remind everyone why our customers use our products: They just want basic file synchronization, sharing, and backup. That's it!
Fortunately, in our case, we have very vocal major customers, so it's "easy" for us to plan features and changes that they will like.
That being said: An important subset of users is extremely confused by files and folders. Figuring out a UI that works for everyone, (power users, normal users, and non-savy users,) is a bit of a holy grail, and a very important problem to solve.