fibod,
If the airlines were recruiting then i would agree with you. A structured hour building program over a few weeks done especially to prepare the student for the CPL would be a good thing. However there may be no recruitment for 3-4 years if some predictions are right. IMHO it would be much better right now to just enjoy the flying and get logging hours.
As for the standard of flying, this is surely what the hour building is about. You are building experience and becoming an aircraft 'Commander'. You say the DIY method is inferior to structured and supervised hour building where you have your hand held and are told how to fly. I was assuming that someone who is heading towards a career as a commercial pilot would be mature and intelligent enough to know that they should be aspiring to acheive a high standard of airmanship in all their flying.
You have a lot of experience of training both Integrated Course students and Modular students so i am not disagreeing with you that what you say is how many students fly, but i am giving advice to someone who has yet to start hour building so they can avoid making the same mistakes as others.