[T]he State of the Union has evolved into a semi-imperial speech from the throne.
Not really. Two points. First, the State of the Union is meant to be retrospective or at least introspective - a comment on the state of the union. A throne speech is forward looking - this is what the government is going to do in this session of parliament.
Second, a throne speech has its pomp and circumstance, with the GG arriving in her Landau and various dignitaries being in the Senate chamber and whatnot, but they aren't like a State of the Union speech, with the applause every ten words or so. Watching a State of the Union is sickening - they remind me of speeches Stalin would give, where the party faithful would rise up and applaud and no one wanted to be seen either not standing, or to be the first to stop clapping. The worst part of it is watching Supreme Court Justices, in their robes, having to stand, but not clapping rather than being allowed to remain seated in acknowledgment of their co-equal status (given the Congress has abdicated its own).
Okay - I'm sure that the comment was an offhand one, given Americans obsession with the idea they were once subject to some sort of absolute monarchy and rebelled because they were routinely whipped and beaten by British Officers (as opposed to, say, being taxed to pay for the war Britain had just fought to make them secure, or being banned from expanding past the Appalachians and slaughtering Indians) from which throne Diktats routinely issued. But the point is nevertheless valid that events like the State of the Union are meaningless, partisan advertising made to the sound of the clapping of trained seals.