I mean, skipping over Linux users that are a significant chunk of the market if you ask me, but lets assume for a moment that Linux home users don't pay much for their software or whatever. What about governments that have adopted Linux? What about Linux being the most popular OS for servers? What about Linux being used in the educational system, like with Raspberry Pi?
And even for yourself, lets say that you'd want to do your own backups of your Skydrive or Google Drive and so you quickly setup your own home Linux box that should synchronize your account. Surprise - you're not important enough.
This is platform lock-in, pure and simple. Microsoft is no better than Google. Don't get me started on Skype ;-)
Because for Google and Microsoft, their services are cloud storage components of their strategic platforms, and support for other platforms is, where it exists at all (e.g., Drive's desktop sync application), a way to ease migration off of those platforms and into the vendor's strategic platform, whereas for Dropbox, the file storage is the strategic product.
Of course, that's why neither Google nor Microsoft need their storage products to make profit directly for them to be valuable.
> This is platform lock-in, pure and simple.
With Drive, which has an API on which third party can build sync apps for other platforms, I don't think its lock in. Its just a matter of prioritizing a tool whose business purpose is customer acquisition for the platforms where the most potential customers are.
I know, I know, it comes integrated with Win8.1, but you can't use a local account, and your options to use SkyDrive with a local account are just nasty workarounds:
http://www.ghacks.net/2013/11/09/access-skydrive-windows-8-1...
This is exactly the case for staying with Dropbox. Otherwise, your cloud provider has more leverage to lock you into their products. Dropbox is motivated to support multiple platforms.