Dontcha know? Millennials are any young kids they don't understand. Who is "they"? Idk, probably boomers, since boomers are any old out of touch people they don't understand.
I first assumed it was made by a millennial but that may be because I am one myself. If we do end up being the next mocked generation I will at least get a little amusement out of genx getting the shaft again.