Yeah, that system for measurement is really wrong.

IMO, the better way for establishing handlebar placement is the position in relation to the bottom bracket - or at least that is the measurement I use for setting up different bikes.

Really, you handlebar position should be determined based on your flexibility and fitness. You are looking for a position that maximizes power and aerodynamic efficiency. It seems to me that too often people are quick to lower their bars for appearance and aerodynamics, thus increasing the hip angle, without considering whether the position is too low, robbing them of power.