I hardly disagree about the WSJ in general but I read the end of this article differently. The author's final question is a good one: why on earth did she take a job working for the very people whose irresponsibility her research exposed? Her answer, assuming it's sincere and not quoted out of context, is indeed naive: she's doing it to change the culture of Wall Street. Well, I agree with what I imagine the author's implicit points to be: (1) the odds that Wall Street culture will change because she took an analyst job are infinitesimal, it doesn't matter how brilliant and well-intentioned she is; (2) this is the kind of grandiose fantasy you have at that age.
Sadly, many young people overestimate how resilient they will be to a culture they abhor, which is how they get sucked in and assimilated. The risks to the beast are negligible compared to the risks to her soul (if this were a movie we'd all be yelling Nooooooooo...) and she's not unusual in underestimating this.
On the other hand, it's easy to understand why any "large New York investment bank" would want to hire her: anyone who can figure out what they do that masterfully will be useful in doing more of it.