I agree with what was said in the article. I'd say one half of programming in general is objective in the sense that either the program works or doesn't. The other half is completely opinion based - be it a design philosophy, choosing algorithms, future proofing APIs, hardening code against malicious actors, etc. This half is very fuzzy because there are no right/wrong answers as it goes more towards taste. IMHO you should try to evaluate the following - "What has the candidate done that makes their opinion worth something". If you can't come up with a very strong reason to give any kind of weight to their opinion, then I'd say do not hire them.