mainframe -> minicomputer -> PC -> smartphone

What's important about cloud computing is not whether jobs run on local or remote hardware, but that ubiquitous connectivity makes it possible to run services on that remote hardware, in aggregate, for many people and organizations. Which is great if there's choice, and the data held and manipulated by those services is under the user's control. Often this isn't so, and this is a step backward from running services on a server you bought yourself.

It's important to fight for an open cloud for the same reason it's important to fight for open software on mainframes. Networked computing isn't new, and neither are the issues it poses for software freedom. We need to continue to provide alternatives, regardless of the platforms they run on.