I thought I'd pipe in here to answer some questions for you given I have some understanding of computers. The bloat you claim that is in Windows is because it needs to be backward compatible. Consumers and business expect modern versions of Windows to be able to run all the software they've bought in the past 15 years.
The online storage systems were developed initially for small business as a method of backing up their data. Until recently, backup systems were expensive and prone to failure. Having a 100 GB online backup system was a fast and relatively easy way to safely store and recover your data. In the consumer market, it was common for people to have their personal data on their computers and a crash would wipe it out. Online backup allows them to store that data and recover it with relative ease.
As for your concerns about privacy, I agree with you that there could be a privacy issue. Yet, in my opinion, it's the least of your concerns. You should be more concerned about the data being collected about you online. Personal information about you is a precious and desired commodity. Companies like Google, Facebook and other social media offer you a free service for your personal data then turn around and use it to generate revenue. That puts your privacy at risk far more using Dropbox to store some movies you downloaded. Just as sinister is the large number of sites that use the http:// protocol not the https:// when surfing. Hosting services refuse to do it because it requires more processor cycles on a server. Using http:// anything you send/receive is transmitted in clear text.
If you like Android, then may I suggest using Linux Mint or Ubuntu?
