Either nobody holds them accountable for when their dodgy intel doesn't check out or i have been misled and torture does in fact yield good results. Which one is it?
Just think of it people got 4 year degrees in a scientific field and built entire decades long career pretending to do something effectively not only to others but to themselves and their superiors. They testified in court dressed up in fancy suits with fancy titles when they were less effective at doing their job than a magic 8 ball.
It would be like finding out your doctor wasn't exactly clear on the difference between a liver and a kidney and him and all his colleagues were just kind of faking it and hoping you wouldn't notice.
The only saving grace that made them look sort of effective was the fact that they quite frequently but not always had ample evidence against the suspect meaning they were far more than average sending them hair samples of people who were in fact already known to be the real killer so they could in theory appear somewhat accurate by for example always saying yes if the hair was the same color which is you know fantastic for black people.
Why would we expect a field of endeavor that is entirely isolated from any accountability to be good at anything?
Honestly, I just think they like doing it.