I remember myself and every other senior engineer on a team once rejecting a candidate and being overruled by management. The guy was hired and... turned out to be as useless as we thought he'd be.
Well, the person might not have been the most skilled guy around, but how hard did the team worked at integrating this person?
I mean, starting with a negative reputation in a team that felt betrayed by your arrival doesn't seem to be the best condition to give the best out of yourself.
There is infinite opportunity to screw over a new hire. Just getting setup in the dev environment on any team is usually 50% undocumented and you need help from coworkers.... it's one of my least-favorite things to do on a new job.
Also undocumented in large companies: how to get ANYTHING done outside the team.
Then when it comes to reviews, especially in large companies, you are utterly beholden to whether or not your manager likes you. I've only ever seen one person the manager disliked get a glowing review, and the manager did it as a joke since they were quitting.
