Earlier quoted context omitted.
Doesn't work on Linux which is what the quote you're referencing is talking about. Office365 comes with it's own challenges. Plus your documents are all scanned and there is no privacy protection, especially not from the US government.
Dropbox is a US company, I don't see how you get better privacy protection there. Plus Microsoft has a petty good track record, they've challenged US government requests for information in court, and fought to prevent the government from accessing data stored outside the country.
It's also limited to just being a shared folder feature.