In Montauk's book he says that admission's officers estimate one in ten recommenders sabotage the person they are writing a recommenation for. He goes on to say that it's not always blatant stuff like, "Johnnyx9 is a complete disaster, I wouldn't let him into your school," but sometimes it's obvious sabotage through faint praise like, "Johnnyx9 has a been a good worker. He gets most of his projects completed on time, and he knows how to use the internet very well."
So one in ten seems really high right? At first I was thinking, "Yeah, plenty of dimwits apply to b-school, I'm sure a lot of them just lack the emotional intelligence or self awareness to pick someone who they know likes them and will write a good rec," but the more I think about it, I think that it's probably pretty random.
Most people try to get a rec from their current supervisor. What are the odds that everybody has a supervisor who is willing or capable of writing a good rec? I had one former manager I was going to use for a rec but the more I thought about it the more I was thinking about the time at the company xmas party his wife was really drunk and kept trying to drag me on the dance floor. So I was getting paranoid thinking of all the reasons why different people might secretly be trying to bring me down.
Maybe there's someone who genuinely does like me, but they would get a sick rush of schadenfreude if they stabbed me in the back. Maybe they have a hidden little jealous streak. Maybe they're thinking, "Oh, this hot shot thinks he's going to go to some hot shot school? He thinks he's better than me? I'll show him who has the power."
So I know the common wisdom is that b-schools think an applicant should have enough good judgement to pick someone who will definitely write them a good recommendation. But there are plenty of people with good judgement who marry people that they think they know, and then later find out they married a transvestite (not that there's anything wrong with that) or that their husband is a lecherous loser, or their wife is secretly addicted to painkillers.
The bottom line is, you never really know anyone as well as you think you do. If you get rejected from a school it's a shame that you can never know if you were stabbed in the back by a recommender. But of course most people never think twice, most people are like "Oh I have great recommendations." Do you really?