Maybe someone is "vastly more qualified" technically but doesn't have any business sense or some other quality that is unknown to the rest of the group. There were many times where I thought that the wrong person was promoted or hired, to find out later that they were actually a good fit. Were they the PERFECT fit? I don't know, but there is value in having history with someone to have a higher confidence they will meet the minimum standard.
There's always someone or some group that is "better" for a job or acquisition or whatever based on some metric.
It's a real problem in my mind for "market information." Generally people go for a product they know, that can fit the bill, over a product they don't know that might be better. Same goes for hiring and personnel etc...