You'd think so, right? But the incentive is to show they were good hires and to quickly eliminate bad hires and if you show me the incentives I'll show you the outcomes...
There is zero incentive to hire for anything except individual performance (superstar) or technical knowledge (basically the same as above) and any success can be humbly accepted while blame can be cleverly diverted onto the team while advancing one's career and looking good to one's bosses.
A better scam has never been perpetrated and it all starts from people trusting too much as is often the case.