Well, I don't respect non-monarchs, because they're inherently lying about their sovereignty - and I'm a Hobbesian fanboy
But I'd say its a fetish for dethroned monarchs (and the more misunderstood or erroneously slandered, the better!) - Cixi, Nicky, Lili, Min, Manuel II, Pedro II, Pius IX - based upon complex attachment issues. Don't much care for royalism, though. Absolutely disgusting.
No, because there is an infinite number of unique GP and a finite number of dummy policies that I can make to register Privy Council members, and dummy policies have fixed bonuses, unlike buildings.