Cloud apps like Google Docs, Hangouts, Slack etc.. were supposed to make the OS less important. It's too bad we're not there yet.
* your documents cannot leave your company network,
* you need features not supported by gdocs,
* you need to work offline,
* you need 100% compatibility for produced files,
* (fill in your favorites)
Lack of MS Office (non-365) availability for Linux is quite a barrier to Linux adoption in more places.