Why are most (if not all) of Jenn Pitts's students successful in this brutal theory job market? What's her secret?
Above a certain level of competence, at top research universities supervisors have a minimal effect on one's career. That students supervised by Pitts are doing well tells us more about them than her.
If there's any connection, it's that Pitts has a research agenda that is very attractive to hiring committees right now, so she attracts students with broadly similar research agendas, which are in demand at the present time.
Yes, she's doing work in a growth area, but from what I've heard she's a good advisor. I ran a panel with one of her current students on it. He talked about how she went from 0 to 60 on his diss topic in a few months, and was already recommending him stuff that he hadn't read. She also showed up to the panel to support him. These are not huge things, but how many of our advisors did them? Seems like she's a good person to work with.