Never mind the security nightmare and the inevitable upstaging by the Wookie... if the Obamas attended, the royals would have to cut at least 100 people off the invitation list just to make sure there was enough food.
The royal family is often accused of living large at the expense of their subjects, but here it is obvious that they are not interested in enabling abject gluttony and sloth.
LOL - excellent observations! I’m sure they want the press to be focussed on how well William and Kate look, not how awful Michelle Obama looks.