I think it is pretty simple, really. In the old days, pre Seve, GB&I just weren't good enough, so routinely got slaughtered. Once the quality improved, although it is only in recent years where the European team really matches the US team, especially in the bottom half, the Europeans simply play better as a team. That is because they are not defending the constitution, the american way of life, the flag, mom's apple pie, etc etc, they are simply playing for themselves, their team mates, captain and fans. They don't represent Europe, which is, at best, a rather amorphous entity, and at worst a hideous bureaucracy.
McGinley totally gets that, and fed and watered it.
I agree with the analysis of Azinger. He did a decent job but lucked out getting Faldo, who was clearly unsuited to the job.
A smart person said (before Medinah), that two things were certain, the winning captain would get too much credit and the losing captain too much blame. I think that happened at Gleneagles. And it will happen again next time. And the time after ....