I'll add my 2 pence worth.
I have a BA (Hons) degree in Geography from a good UK university and the equivalent in Law, together with the professional examinations required to become a solicitor; and passed the ATPL with ease about 10 years ago.
Firstly, university degrees vary in difficulty. A first class degree from an average university is seen as the equivalent of an Oxbridge 2-1. Pretty much anybody can get a 2-1 from one of the new universities - my ex-sister-in-law did and she struggles to speak in sentences.
Second, a degree in humanities subjects is as much about 'learning how to learn' than actually gaining knowledge. It's about absorbing ideas from the more educated and learning how to articulate thoughts of your own. I can vaguely remember what my dissertation was about but haven't a clue whether I still retain anything else in my brain from those 3 years on the Strand. I suspect the same is true of most people who look back on their degree subject. It's wrong to compare the value of a degree with the tick-box approach to the ATPL.
Third, I guess science based degrees are the most comparable with the ATPL. Yet those studying, researching and writing essays on technical matters are surely becoming more learned than an enthusiastic budding pilot who is simply reading a book of notes specifically prepared by a company familiar with the bank of multiple choice questions? As most graduates from the ATPL examinations in the past ten years obtained averages over the 14 subjects of over 90% one has to question the value of that qualification.