You can certainly learn by trials and errors, but to be honest you'd learn a lot more if there are professionals to help you.
Second issue is programming 15 hours a day seems a lot. I can't even stare at my screen for more than 7-8 hours a day. That's a lot of work...
I do like the idea, and I think traditional curriculum should adopt part of this. I advocate my department to do "student seminar" as elective, but the department always refuses by saying "your employers don't see the value and have no way to justify your ability by taking this elective."
I like professors to give students more freedom to build things and show to class their progress.