It doesn't take 50+ hours to learn to keep the blue side up and the brown side down. The 25% on the ground and transiting isn't wasted. It's all stuff that needs to be learned and be comfortable with, but, only if it's something that the student will actually get use out of.
If you want a RA style, CASA licence, probably not required, if you want to be a PPL and be able to fly CTA/Busy aerodromes and faster more complex aircraft then its good experience. But I do agree that it does hurt when .3-.4 each flight that you are paying for is on the ground.