I agree with you that I think working for this company and not having an ethical objection is a red flag.
But the interview environment is fraught. Is it really obvious that no candidate would think "this question is a trap"? There's a lot of interview advice that says your answer to this question can only ever hurt you, so be as bland as possible.
Some employers want compliant employees who don't rock the boat. Some employers will hear complaints about proctorio's software and hear "SJW shit".
I don't want to work for those kinds of employers, but I sympathize with people who want a job and might fear that their honest answer could be used against them.
Ultimately, I think I have to come down on this policy being a bad idea, however understandable.