"apparently having taken the baton from the desktop, which has failed to live up to years of expectations and promises."
Linux has not failed to live up to expectations and promises. It works perfectly fine in desktop capacity, whether that be for personal or business use. Its use in a business desktop setting requires an IT Dept with sufficient knowledge and commitment to facilitate a migration. It requires management that will commit to financing a migration and it requires training of end-users. Obviously in any company this becomes a major project which requires thought, testing and cost-justification, especially if core applications have to be modified, migrated or replaced.
This has nothing to do with the ability of Linux to perform. At a personal desktop level, I only recommend Linux now to people who want a new PC. I can't be stuffed supporting them when windows fails to perform adequately due to some action on behalf of those users. Windows does not adequately protect inexpert users from their own actions. When will it live up to expectations and promises? :)