It irks me tremendously when we take this attitude. I think the problem is that developers have no spine or backbone and are used to bending over too easily - largely because of the personalities we tend to be "nice people".
As developers we have a number of failsafes and checks and balances in our processes: code reviews, TDD, unit through to integration testing, audit trails on every byte of code changed etc. To suggest that a wrong hire is "too costly" is ridiculous.
Compare this with a management consultant who is often on client site alone and whose work is heavily based on personality - "the airport test" - any wrong move could end up risking the client relationship with the business.