El Cid
What an excellent idea. Having progressed from gliders to Tigers I never did anything but glide approaches (often with lots of side slip) until I had trouble on a check flight when asked to do a power approach and I had forgotten how low and far away you had to turn finals in order to keep power on until the threshold.
Returning to my original point about 3 degree glideslopes being the order of the day at PAPIS equiped fields, glide approaches are so rare that you seem to have to get ATC clearance for them. I'm not sure that your idea would go down so well there.
It is also possible that, on some more modern training aircraft, the poor elevator authority for the flare from a glide approach may make learning more difficult (instructor's job harder), and cause even more damage to C150 nosewheels.
I'm still waiting for some PAPIS dominated instructors to contribute to this discussion.