I think it's ridiculous to say that you only get the "right" to be upset if you're from the specific place mentioned in this particular instance. You have every "right" to be upset about someone insulting someone else, and you not being the target doesn't take anything away.

To take a pathological example, I have every right to be upset about neo nazis running racist advertisements, even if I'm not a member of any of the targeted races.

A better argument in defense of the commercial would be to say that it didn't really do much harm: there wasn't anything malicious like the neo nazi example, just a surprising transition to Groupon's purpose.