Are State of the Union Addresses Getting Dumber?

The Guardian has an interesting chart applying the Flesch-Kincaid readability test to State of the Union addresses. Its headline says that the "linguistic standard" of the addresses has declined (Really? That's not really what the Flesch test is all about) and concludes that the addresses are getting "dumber." First of all, aren't State of the Union addresses primarily to be heard, not read?  Second, is it truly dumber to speak in a way that more people are apt to understand? When you write your summations to the jury, are you worried about their linguistic loftiness or whether you bring the jury to your side? Still, interesting chart.