It wasn't the hat. REI ignores everyone, unless you have the exact right tree hugger look.
That's not even a joke. I went to REI occasionally, but regularly decades ago. Then I didn't go for a long time. Then maybe 5-6 years ago, I went back.
During my earlier visits, I noticed no difference from any other store, and I certainly didn't wear Birkenstocks and a Sierra Club t-shirt when I went. Employees were at least as friendly as in any other store.
During the latest few visits, I absolutely saw a difference in the employees. I normally wear jeans and a t-shirt, so no advertising of my politics. They were not as friendly to me, and you might say unfriendly, compared to how they treated the skinny people in the convertible hiking pants and stuff. I was actually turned off by the "new" REI environment and quit going.