Interviews at top business schools are nothing but partitioning and mathematical analysis. Google “business school case interviews”. Modern business is analytical and quantitative. Over 50% of my classmates came from software development or engineering backgrounds. This mix is not at all unusual.
I think your reaction may be to the PHB types — who aren’t good at any of that but they have soft skills (aka people like them) so they get promoted. Honestly the biggest truism in business is that it’s better to be liked than to be good.
That's an incredibly rare thing. To date, the only systematic exception to the above rule I've encountered have been from certain European schools (mostly French: HEC, ESSEC, etc) that have a math-heavy prep-school curriculum to get in.
From what I've seen though, this is very much exceptional.
Simple shit like p -> q, orders of magnitude, independent probabilities, partitioning[0], and the classic correlation/causation go completely over their heads.
At the risk of sounding arrogant or elitist, there's a reason the peripatetic school inscribed "let none but geometers enter here". By and large, a mathematical education structures thought in a way that nothing else can.
[0] My personal pet peeves. People seem unable to break concepts down into component parts that both (a) cover the entire problem and (b) don't overlap.