I don't know what groups of people the royal couple were meeting with, but if they were working people, the couple may have felt formality placed an undue financial burden on them, and rightly so.
On the other hand, it is my experience that people enjoy dressing up for a genuine and very special reason - in contrast with an occasion such as a cruise ship dinner.
In any case, from my distant shore via still pics only - looks like they did a marvelous job.