Ok, so do users really rely so heavily on Ubuntu One? If so, then why do you shut it down? If no, then why do you say they rely on it?
I believe they don't rely on it.
"The Ubuntu One file services will not be included in the upcoming Ubuntu 14.04 LTS release, and the Ubuntu One apps in older versions of Ubuntu and in the Ubuntu, Google, and Apple stores will be updated appropriately. The current services will be unavailable from 1 June 2014; user content will remain available for download until 31 July, at which time it will be deleted."
1.5 months? Really?