What's the goal? Increase headcount at any cost?

Improve the ratio of compensation to workload in the hiring employer's favor.

The reason someone is unemployed or is desperate might correlate (inversely) with their ability to produce high workload.

Or it might just be a totally unrelated layoff that axed a whole team / org / whatever.

Might correlate with ability. Which - let's be honest - gets rounded down to "is caused by inability", just in the next step, in the name of Efficient Hiring Process.

Find the occasional spark of brilliance someplace where others aren't looking?

That’s it. Not everyone lives a life that leads to a perfect resume.

And for that matter, some people do live that kind of live but still fall through the cracks. Not everyone is lucky enough to graduate during a strong economy, apply to exactly the right jobs at the right time, etc. There's a lot of wasted talent out there that many businesses have little interest in seeking out.

This! One of the best developers I've worked with used to be a carpenter who had a kid with Down syndrome. He taught himself programming in his spare time. Smart, extremely driven and knew how good we all had it.

Finding talent

In my experience, it's just to hire the people that got passed over by other companies but still have some skill. You dont have to pay as much and they might also be more likely to stick around longer if they have trouble interviewing at other places.

I'm stuck in my job and I get paid less than people with lower tenure and credentials. Due to a disability, I don't have the social/political skills to get promoted in my org nor feel comfortable job hopping. It's funny though because every team I've been on has had managers or TLs telling me things that equate to 'you should be at the next level' such as "if you were preforming at this same level on another team you would probably be promoted". I had an interview internally recently and was told that I "found more errors than was expected" for my level.

So yeah, get disabled people like me so we are less mobile, work above our level for the technical work, cost less, and can't get promoted easily.

There are lots of good people who are unemployed through not fault of their own. The goal is (as always) to find good candidates. Because of some company's weird aversion to those not already working, the pool will be stronger by including those with other job histories because it doesn't really indicate who they'll be as an employee.

It's just cargo cult hiring.

Hiring talent at a steep discount.