> It matters because a hereditary head of state position (actually, any governmental/establishmentarian position) is a terrible symbol in what should be an egalitarian society, no matter if you have political power or not.

Why should society be egalitarian? Nature isn't.

Why shouldn't society recognise the heirs of great men specially?

I think that the ideal government has voices for the great mass of the people; for the magnates; and for a monarch. The U.K. system — until Tony Blair destroyed it — was good for exactly this, although the removal of the Lords' ability to block legislation, and the addition of life peers were recent mistakes.