People aren't making hiring decisions based on protected classes. Rather, they're looking for qualified candidates in new areas.
One thing that's common is for people to recommend their friends for jobs. Most of the time, their friends look just like them, because that's the kind of friends that people make. If you base your hiring process around this easy source of candidates, you end up not talking to a lot of people that would be qualified for the position. "DEI" can be as simple as "in addition to employee referrals, we're going to hand out brochures at a career fair".
They actually have been recently; Especially in academia where after racial-based Affirmative Action was ruled unconstitutional, wealth-based AA has been helping economically disadvantaged individuals—even including white men.
One thing that's common is for people to recommend their friends for jobs. Most of the time, their friends look just like them, because that's the kind of friends that people make. If you base your hiring process around this easy source of candidates, you end up not talking to a lot of people that would be qualified for the position. "DEI" can be as simple as "in addition to employee referrals, we're going to hand out brochures at a career fair".