Because it was attacked for being underpowered. HR did nothing but provide happycap management. Except build Royal Guards but no one built them because a) they were sorta weak in that timeframe and b) players often shun building units that vanish when a civic changes. So Royal Guards were almost a litteral non-factor. That left one function for a medium cost civic. As compared to the same function, now at low cost with the additional functionality of the old Aristocracy civic. Aristocracy can be adopted early in the game, and left in effect for hundreds of turns. So now even the 7STR Royal Guards might be built. (That part is a Good Thing.) So there's your answer. It is the combination of features and the low cost that is the new issue.