In fact, I also wrote "in tune with a PhD mindset".
I am assuming that a PhD student did not choose his PhD according to particular mental abilities, he was top 5% in doing research and solving real problems instead. I am also assuming that a PhD student has no time to study quantitative finance during his PhD (although I personally know some PhD students that do not actually work for their PhD, it is sometimes allowed if your supervisor agrees).
Then, I personally found that banks mindset is much closer to the university mindset, and the possibility to start as an Associate because of your PhD is a very strong plus that rarely a company would consider.
I also know some Applied Mathematicians (with a strong background in Data Science) that managed to get a job at some top trading firms, as well as IMOist that got a job without a PhD... but... I'm pretty sure that my reccomendation is the easiest and the most normal way to get in while doing a PhD (and without any commercial experience).