Interesting article in that vein Grey in the Post today by Donn Maclean.
I agree with what you say, but what is maybe confusing things is generally speaking, really good horses have won the Irish Derby in the past 10 years - Galileo, Sinndar, High Chaparal, Dylan T, Hurricane Run, Alamshar, Fame and Glory - but those in behind haven't generally been up to much.
Is the pattern commitee European? If so, I don't see how they allowed the GP de Paris/Jockey Club distance switches as this was always going to affect the Irish Derby, and also the King George.