We have rec'd an invitation to a wedding at a resort in Mexico. There is no way we are going to spend the money to fly and stay in MX for someone's daughter that lives several hundred miles away and we have seen only a few times. Why would the bride's parents send invitations to a wedding that no one but family will attend? Shouldn't they have a reception locally for people they are expecting gifts from?
Part of it could be that they're flaunting the fact that they can afford a destination wedding. They don't honestly expect you to shell out the money to go to mexico for someone you barely know. They just want the recognition and gifts!