The basic problem is that a pilot needs to know when the approach needs to be corrected.
The pilot needs to have some sort of 'error-ometer' to assess this. With 'point and power', it's easy - the 'error-ometer' is the ASI
if the touchdown aiming point is kept stationary in the windscreen.
But with the 'other' technique, pilots have to assess whether they are above or below their desired glidepath. That is a skill which is MUCH more difficult to learn to the same degree of precision as 'point and power' achieves; most pilots using this 'other' technique take a long time to develop their personal glidpath 'error-ometer' and often leave things until very late, then add a huge amount of power and attempt to get back onto their original glidepath. This is particularly true when landing on a long runway as, unless he/she is grossly undershooting, the approach probably 'looks OK' to the student pilot, although he/she might eventually land anywhere within hundreds of feet of the correct touchdown point.
With 'point and power', pilots rapidly gain the skill of keeping the touchdown aiming point steady in the windscreen. As experience is gained, corrective power changes to correct speed errors become smaller, because they are applied sooner. I used to teach turning final at approach speed +10, then roll out, select full flap, adjust and trim to approach speed before concentrating on 'point and power' all the way to the flare. Dead easy - and that's why 'point and power' students usually solo at least 2 hours sooner than 'other' technique students
But others persist in making things TFD for the student pilot to cope with particularly, regrettably..... They probably teach them a mnemonic as well...
When you learn to teach 'point and power', you should also be taught the 'glidpath error' sequence - it is
not essential to fly a 3 deg glidepath as 'point and power' can be used over a
range of acceptable glidepath angles, which you demonstrate to the student from a long, straight-in approach flown at a constant height of about 4-500 ft.
Probably only those playing airliners and flying long final approaches insist on 3 deg visual glidepaths in light aeroplanes.