> Because many people who hire think more vetting reduces the chance of bad hiring.

I don't know why you are answering for bluGill, and bluGill is answering for you. This is frustrating to me, because you don't appear to be of one mind. Unless you are secretly of one mind, one person behind two HN accounts.

In any case, bluGill's previous comment suggests that job interview vetting is rarely enough: "I've seen very few people obviously incompetent. As such it takes a while to prove they are incompetent. They do write working code and get it through review. Often the only clear sign is nobody likes working with them - only after you get rid of them do you have concrete evidence that they weren't contributing (that is the team got as much done now since they no longer were stopping their own work to help the incompetent person on things that it is never clear if should have been figured out alone)"