I think two things are at play here: 1. The chances of discovering a potential employee are much higher if they are passionate about their field. Passionate pe

I think two things are at play here: 1. The chances of discovering a potential employee are much higher if they are passionate about their field. Passionate people make a lot of noise. The OP acknowledges this. 2. I never said you should always higher passionate people. For example, some passionate people are unlikely to get things finished (they're more likely to be excellent at starting projects). I agree with you about this being a rubbish (and potentially illegal) HR policy.