Well, the word of a nobleman is worth more, because the nobility is the guardian of the national spirit more than any other group, outside the Church of course. It was very good of His Grace to speak out specifically as a nobleman.
I agree with his message, but I don't see why I or anyone else should be impressed with a person's pedigree. My attitude is always "Well, perhaps your distant ancestors were illustrious and did great things centuries ago. Now what have you accomplished?" Keep in mind that the USA has its own de facto royal dynasties - Kennedy, Bush, etc., and none of them are too impressive.