Yes it was, at least indirectly. The cmd key is designed to invoke shortcuts in the GUI layer and not conflict with anything that's a legacy from the text-mode style of interaction. That's why it's a special different key.
This is an accurate way to think of what the relationship between the command key and the control key on the Mac is today.
Historically, the Mac initially didn't have a control key. It was introduced later to accommodate terminal emulation. There was no "legacy" to accommodate for the Mac of 1984; it was a new platform with a completely different UI from most other computers of the time. Since then Control has been increasingly used as a general modifier key -- though still limited compared to command, for exactly the reason you state.
