I'm not sure why so many people seem to think that a maths/ physics degree is so helpful to ATPL exams/flying. (Not just on this thread - seems to be a reasonably widely held belief in my opinion)
I have an engineering degree and the maths/physics involved in that have next to no relevance to me as a pilot (unless airline flying is going to take me very much by surprise

).
Basic maths/physics knowledge is required but I have never applied anything I learned beyond O-level. (The world of Laplace transforms, fourier series, imaginary numbers and generally the type of thing that covers the blackboards in biopics such as 'A beatuiful mind' and that one on Hawking recently are irrelevant to the stick monkey at the front).
As has been mentioned, a degree shows the ability to learn and apply oneself, but so does a frozen ATPL (and if from a non-academic background perhaps even more so).
Airlines have minimum qualification requirements because that is all that is required to do the job. Anything beyond that might be coonsidered a bonus - whether it is a degree or an extra five or six years in the real world dealing with real people