It's about access to resources that you won't have not being part of a university. This is especially true for physical sciences that require expensive laborato

It's about access to resources that you won't have not being part of a university. This is especially true for physical sciences that require expensive laboratory equipment. However, even for something like CS, having access to good lecturers and courses is very helpful. Of course, the open courses being put out for CS and Math is certainly is changing the picture for these fields. I think they are great. The point is, learning in a bubble is not nearly as useful as learning from peers and those more experienced as yourself. It's also the case that few people have the discipline to go through the important but sometimes dreary exercises required to learn these topics. Having structured learning programs helps with this too.