It's an interesting point you bring up - that of ignorance
shrinking.
Even among the "willfully ignorant" [my in-laws revel in their
ignorance. They KNOW better but _choose_ ignorance as a sort of
noble badge of "cool-ness") - THEY TOO, are less ignorant even
as they pretend to be.
It can be hard to see it sometimes; in online debates (which are
commonplace) someone may _appear_ to be dumb and yet, they're on
a computer. They're communicating. They're expressing opinions -
in short, the person who _appears_ ignorant about 'everything' -
is no different than the person who 'appears open and
intelligent' because:
They're communicating on a common platform, which requires
implicitly, less ignorance.
So, I'm rarely fooled by someone who appears to be ignorant
online. They're not ignorant. They're just expressing their
opinions that have the veil of ignorance.
In short, you gotta be smart to appear dumb in a smart
environment.