This is wildly dogmatic and not really based in reason. The risks of a relationship are evident, but what about the upside? Imagine the chance to vet someone over time for cultural and professional fit for a role that they might excel in. When a company gets large enough where there is zero interaction day to day are there no possibilities that this might work? Setting aside a lack of disclosure, is the leverage so great that someone is a liability having a social context? It just seems like people are pretty black and white on this.
TL:DR Devils Advocate Postion