Fundamentally pass rates and number of failures is simply another gate, especially for newbies.
Post ATPL you are going to need be able to pass exams (Type ratings, conversions etc. .) so you have to get used to it, develop exam technique, etc. It's one thing failing exams on your own dime, if you're persistently struggling with the ATPL for whatever reason it is going to ring a bell with the companies - they really don't like the idea of perhaps giving individuals extra time /extra days off the line because the individual has a problem taking exams.
it goes to show that you really can't take your foot off the pedal when it comes to flight school performance
It gets slightly easier as you gain experience but FWIW these days courses are increasingly compressed - if undergoing any training (conversion, left to right etc) you can't ever take your foot off the pedal.