True, however in the UK anyway the level of practical flying skills achieved is driven by one main thing i.e. money, and most students understandably do the minimum necessary to pass the skill test. Ground studies generally cost little or nothing in comparison to airborne time so the more time spent preparing the flight the less time wasted in the air. The other thing is that a lot of people do not stop learning once they pass their test and get measurably better the more they fly on their own. So yes I agree with you in part but I did the same thing and made my fair share of cock-ups along the way (and still do occasionally it must be said). The one thing you can't buy over the counter is experience.