Many companies (including tech) started DEI policies in order to broaden their pool of candidates and make internal promotions more merit-based. The stated goal was to attract better candidates and make their services and products more in line with their customers. Made sense.
A few years later, many are capitulating to political pressures to drop those programs.
Thing is, the original problem still stands and these shareholders (who presumably mostly care about their investment) know this. That's why they're voting down these proposals. They could call Costco and Apple West Coast liberals, but not Deere. It's just smart business.