If you find it useful, then certainly someone else may find it to be so as well... go for it! Explain why it's useful and others may appreciate it.
My two cents: If you're only running the "foo" command - and nothing else in the actual "button" though - I'd encourage you to just copy and paste the User Command "code" you created directly into the button. You certainly don't need to change it - but if you're inclined to share it with other users, I don't see the need to send them on a multi-step process to copy what you've done when you can just use the steps from this sticky post to post a complete button definition they can easily add to their toolbars with a minimum of clicks...