Why should the elected leader of the Labour Party have to kneel before the heriditary monarch?

Why should the elected leader of the Labour Party be required to kneel before the monarch - a person who inhabits the role simply because her ancestors happened to head up the biggest gang around? While there are many given voice in the public discourse, who like to look backwards to the good old days of the 19th century, surely a return to the divine right of kings is not on the cards?