I'm a boomer and trust me, we had our share of functional illiterates, innumerates, and all-around ignorant people. Look at the 60-ish people you know. Allowing for greater life experience (e.g. remembering Dr. King rather than having just read about him), do we seem as a group so uniformly wonderfully educated to you? I thought not.
I think millennials are on the whole just a little better educated than we were. The problem is that they need to be a lot better educated.
The world is changing faster. Information sources are more varied and less reliable. In an era where it has never been easier to surround yourself with crackpots you need to be a more independent thinkers than boomers, who despite our counter-culture pretensions are as big a generation of sheep as this country has ever produced. When we entered the workforce there were lots of good-paying jobs we could do with just a three R's education. For millennials those jobs have gone overseas or are being lost to automation.
So in the current environment, the average person needs capabilities that would have made him elite in past generations. That's why so many more Americans go to college: 68% in 2014 vs. 45% in 1960.
So it's no surprise if the average college graduate isn't as impressive as the average college in past generations:you're looking at a different sample, one more representative of the population as a whole.