I appreciate that, and I often encounter the same attitudes. However, if you will observe the emphasized portion above, you are essentially supporting the premise that this is where most people reside, if so many people are trying to paint you into those corners. YOU may be contrary to that, but I would not say that you represent what is typical.
I'm firmly of the belief that's not where most people reside. What I think happens is that we can understand and contextualize the political, economic, and spiritual diversity within ourselves, but when it comes to looking at others we tend to oversimplify them and cram them into a convenient per-concieved understanding of label x, y, z, q, etc depending on what our initial impressions are. There are actually biological reasons for this as well. Simply put correlation is good for us as an evolutionary trait, particularly when there isn't perfect knowledge of a thing. Something glowing red may be hot so I'm not going to touch it! Animals that growl and have sharp teeth may hurt you so be cautious! Brightly colored reptiles may be poisonous so beware! Not perfect examples because they are pretty simplistic compared to the depth of political, economic, and spiritual views, but it is a common human tendencies to categorize things, people and beliefs included. That becomes problematic though because when we fill in the blanks for these vastly more complex topics we have a much greater mathematical chance of getting it wrong, or of grossly over simplifying.
I don't even think it particularly malicious, it is merely a tendency of all of ours that we have to keep in mind so that we can reserve judgement and seek out better information on which to base our opinions, beliefs, and actions.
So, to rephrase a bit, while diversity may exist, I still maintain that most Americans these days tend to do little more than see a line in the sand, jump to one side or the other, and adopt a ready-made set of ideals and talking points. There is not a lot of room for individuals like you or I in that equation.
And I think that's the way many people see most people, but when you ask them about themselves they'll usually claim to be an exception, or "not like that", and once again I think that is because of the above condition based on information asymmetry.
Now, I get what you are saying, but I do maintain that our political system leaves these "diverse" groups pretty marginalized, and ultimately that line in the sand is all that system will support, and that's where the diversity you speak of start to matter less and less.
I think it matters less simply because we ignore it for the above stated convenience reasons, and one problem that I have with media personalities is that those people tap into those oversimplifications and two dimensional labeling and exploit it for profit or to further there own image. And these are often times very smart people, aka people who should know better.