However some of the knowledge will be required, such as the gas laws and electromagnetic induction etc. So while the knowledge from a complete Physics A level isn't required, I'd say knowledge over and above GCSE level is definately a good advantage and making these requirements is just Excels way of ensuring that all applicants will have the required knowledge.
Sorry, but you're wrong. You do not need to know the principles of gas laws or electromagnetic induction. You will be taught all you need to know about these subjects when doing your ATPL ground subjects; once you have passed them, you will probably never touch most of this stuff ever again. Having maths or physics A-levels may save you a few minutes' study during the ground exam phase, no more than that. Once you begin training on modern aircraft, you will find that the training will not require any kind of detailed knowledge of scientific principles.
I spent the first 22 years of my flying career in the RAF, including many years as a Qualified Flying Instructor (QFI). The RAF requires a far more detailed knowledge of basic ground subjects than any airline employer I know of, yet it
still asks for maths and a science only at GCSE level. Many - probably most - of my pilot colleagues both in Virgin and the RAF do not have science or maths beyond that level and have never been at any disadvantage.
There is nothing to justify Excel's demand for maths and physics at A-level other than the prejudices of their recruiting/HR department.
Scroggs