So it wasn't the questions themselves, but when you start asking about why you moved from this city to that, or why did you choose this school, etc. Maybe it's because your SO got a job there, or some other personal reason.

I get that it's totally an innocent intent, but there are much better ways to assess a candidate's soft skills, that is strictly related to their professional experience.

Okay, my Original Point was that maybe one of the soft skills the test is assessing is the ability and willingness to share their personal self in a positive and constructive manner.

Many if not most people find us a desirable attribute in coworkers and workplaces. I get that it's not for everyone, but not every workplace is a good fit for everyone.

I think you're getting some rude comments because of exactly this fact

honestly that is something I value as well, but I think that's when a lot of bias can come into play. Perhaps that bias is desired for culture fitting, but you still have to be careful if protected-class stuff comes up and you want to reject the person.

fwiw, when I interview candidates in a technical interview, I still attempt at some small talk to get a sense of "can I have a normal conversation with this person"

(appreciate the sensible responses btw!)

Sure, I think I agree that once you get into picking people based on cultural fit, you run some risk of discrimination suit, real or unreal. It is a tricky area.

You can say the wonderfully vague "my partner" if you don't want to reveal your marital status and sexual orientation