He is not complaining that the file can or cannot be backed up, and Dropbox is no backup service by the way.
He is complaining that their software hangs on open file instead of doing the sensible thing and not using 100% cpu until the lock goes away. That has nothing to do with "how computers work".
Don't forget Amazon Prime. The content isn't that great, so I wouldn't go out of my way to get Prime for the streaming, but it's "free" with the shipping which tons of people use.
The days of .COM/.EXE got me started in programming. I thought, gee, I have some game ideas. So I looked into BASIC, seemed great, but the distributed files required a certain flavor of BASIC. After looking into C for developing standalone binaries, I switched to C. Programming something like DOOM required 'vertical strips' calculated across the screen and other graphics gems, so I learned about graphics gems and programming. C++ and TurboPascal and then Delphi and VB6 were released. Seemed like a never ending journey!
Today we have CocosX for cross-platform sprites so games can be quickly deployed on multiple platforms, plus Unity and Unreal engines for 3D development. It's much better today, but I wonder what it's like to not have the kind of background of learning that I did.