Interesting report, and I think some of the comments here demonstrate why it is useful for the EU and other organisations to commission research like this (rather than each member state paying for it separately).
We all tend to see things through the prism of our own experience, so we assume that the UK is an example of why 'everyone is doing it'.
actually, looking at this research, a more interesting question might be 'why are we doing it less than lots of other countries', and also 'what would the unintended consequences be if we switched to a broader qualification at age 18 and / or introduced a more transparent university admissions process based purely on the points actually achieved by applicants to a given course?'.
Both of which propositions seem immediately attractive to me, but perhaps less so after reading this!