This is why I would probably hire a person with a math degree over many most masters level industrial engineers.

As backdrop, I am a systems/industrial engineer, who never formally studied it. My undergrad was mathematics, but just kinda landed where I was (young company doing consulting on the side (maybe 8 or 9 of us in that division), they needed someone smart and I was available, so I spent an inordinate amount of time reading graduate level industrial engineering books....well, not inordinate, just evenings and weekends). I would become an expert in a particular study over the weekend (had to man, fake it until you make it in the real world sometimes). I'm closing in on a decade of this work.

Back to my point, I have had to deal with more kids coming from college with their masters in industrial engineering who don't know how to reason or even fathom how to approach something that wasn't spelled out to them in a step-by-step manner. Alter it by one little bit, and they tailspin and have no way to approach the new problem. Every problem we approach is new, so it becomes very frustrating for them. They don't usually last. This is not everyone, there are some very brilliant people who hack it. The point, I have yet see someone with a math degree pick the art of engineering up, relatively quickly, and still be able to adjust their methodologies to new problems.

TL;DR - In my experience, it's easier for someone with a degree in math to learn how to design warehouses, networks, and material flows, than to teach an industrial engineer (with a more advanced degree) how to think, adapt, setup problems, and solve them.