Interestingly on flying scholarships the RAF required us to teach Point and Power to prevent students from going to low on the approach. Many held a nice constant airspeed as they poipoised down the approach path. As someone who was taught P&P from square one, it was going back to what I had been taught; many instructotrs had neither tried it nor even thought about it as a technique.
As DFC said its a state of mind, both power and attitude affect speed, and ideally it should not be possible to tell which method you are using. However, there is quite often a time delay whilst the student reacts. If you are using attitude for speed on a powered approach then that reaction time manifests itself as deviation from the glideslope. By holding the glideslope constant (Point) then you now have only one variable to contend with, Airspeed. (Power) does that quite nicely resulting in a more stabilised approach. Clearly, if you have no power then you can only use attitude to maintain airspeed.
You use Elevator to maintain the vertical position when Straight and Level and when turning so why should it be so different on an appraoch. Many early aircraft had a high nose attitude at approach speeds meaning you could not see the landing area consequently, the only way to control the approach was to use elevator for speed. If you can clearly see the landing area you have two choices, neither are exclusively right nor wrong.