Why would MS think that anyone would want the entire contents of their personal hard drive to be uploaded to a cloud? And further, why would it make sense to delete the local files if someone deleted them from the cloud? In what world does this make sense. It is a poorly designed system and it's a huge violation of privacy of your customers. I have nearly lost all my files because I "deleted" them from OneDrive. I guess I stupidly thought that my local files were safe, as I did not try to delete them. OneDrive, in its ineptitude, decided for me that since I didn't want them on some server somewhere, that I must not need them at all.
Please move to an opt-in model instead of the current opt-out model. And upon opting in, there should be a tutorial of the functionality of the software. A tutorial that an idiot can understand. And it should default to sharing a single folder, not the entirety of a computer.
If it was designed this way to artificially increase "usage" of the terrible software, you did a great job. But you increased usage to impress whoever at the cost of your customers' happiness and at the cost of their privacy. As a basic rule, people don't like their personal possessions (including data) being taken without their knowledge or consent. If you are going to steal our data anyway, at least be sneakier about it.