Diversity for diversity's sake is nothing more than affirmative action and can make no claim to being part of America's greatness.
Diversity, to the left, means minorities get even with, minorities triumph, minorities get payback. That's what diversity means.
No company can say our country is great because of our diversity. They can say it but has nothing to do with it, literally nothing to do with it, how diverse you are. "Well, it just means that we don't discriminate. It means that we value all people." Fine and dandy. But unless your company makes something or has a service and you have an atmosphere where people working for you can become the best they can be, it doesn't matter what your workforce looks like, dummkopf.
The original United States, the founding of America was indeed a shared culture. And you could argue that there was a diversity from the founding days, but not the way the left defines diversity today.
