Is it ironic that so many don’t understand irony?

Recently I was walking and talking with my co-worker, who is a freelance writer and aspiring journalist. We were talking about the fact that our employers were providing us with a Thanksgiving lunch the day after Thanksgiving, and she said, “It’s so ironic!”—all emphasis and drawing-out of syllables possible used on the last word.

This is a smart girl I’m talking about. She’s a college graduate and has done her fair share of writing and reporting. Even so, she doesn’t know the definition of irony. Merriam-Webster defines irony as:

1: a pretense of ignorance and of willingness to learn from another assumed in order to make the other’s false conceptions conspicuous by adroit questioning—called also Socratic irony.

3: a) incongruity between the actual result of a sequence of events and the normal or expected result; an event or result marked by such incongruity

b) incongruity between a situation developed in a drama and the accompanying words or actions that is understood by the audience but not by the characters in the play—called also dramatic irony, tragic irony