I would argue that's not fair at all. Think about what you're saying: you're saying that your Mexican restaurant should effectively not have to worry about your competition providing a better job to your staff than what you offer. That changes the dynamic so that you don't have to worry about doing your best to retain your staff.

This problem is the crux of why Silicon Valley is so successful (where you can't do this there) and tech hubs in other locations aren't anywhere close to as successful (where you can do this there).