You are not alone.
So I have the "fancy coastal intelligence" you talk about, or at least the degrees that signify that I do (although I got them in relatively remote places in Kentucky and Tennessee, so not exactly coastal). But I come from a family of school teachers, carpenters, and construction contractors. In other words, the kind of people who do not tolerate a lack of common sense in their children and try to teach it at every possible opportunity from birth on.
I've personally seen this exclusion at work many times. Political correctness police, social justice warriors, whatever you want to call them, don't care for inclusion of anything that doesn't fit their narrative. They will seek out your differing point of view, scream about it, try to isolate you from help, gang up on you, force you to apologize, make you give up, then appeal to higher authorities to marginalize you/exclude you/fire you, then have something like a show trial about you, and then finally declare victory and celebrate. But their celebration will usually contain notes of "well I never intended things to turn out like this!"
Obviously I've seen this whole process happen a time or three in various corporations. Those who were excluded/marginalized/fired often had no real idea what they did in the first place.
That's the end of my rant, which is only tangentially related to yours, but yours resonated with me because a lot of what you said reminds me of myself.