The second reason why I have always advised my teams not to consider “culture-fit” when interviewing prospective employees is that it is a covert way of discriminating against people who have otherwise protected attributes (race, religion, gender, sexuality etc).

There's a difference between "culture fit" and "hive mindedness". I've seen singular employees turn a good workplace into one with strife because that one employee has vastly different goals about how to run things, and it doesn't go away until that employee is fired.

Also, it's not about discriminating against future hires. It's about not hiring shitty employees who would discriminate against their own co-workers.

Huh, and here I thought culture fit just meant your ability to hold a basic conversation about a random topic without completely locking up (which has gotten me several jobs)

Perhaps "like-minded" is the wrong term, here. The idea is to find people who are just looking for a way to say "do I see myself working with the people on this team?". If you go through the questionnaire, you will see people also should answer "what answers are also acceptable" and "how important their answer is to you".

The questions are not about checking people's backgrounds or rooted in any type of personal topics that could lead to discrimination. They are asking things like "what do you think of scrum/agile" or "do you think that it's okay for companies to use data on the web for AI, if this means more free services for people?".

You should hire people based on their ability to perform the job, and nothing else.

That's a given. But unless we have perfect equilibrium between supply and demand for labor, there is always one side that will have a number of options (candidates in the down-market, opportunities in a growing cycle) and they will always be asking themselves "of all these acceptable options, which would fit best?". No one will just say "good, we have 20 qualified candidates coming up, so let's throw a dart and hire whoever it lands on".