Questions like "Why do we have to write X, when framework Y does it for you?" are why I dislike the reinventing the wheel analogy, especially when it finds its way in education. There's no substitute for the deep understanding you get by solving a complex problem yourself from beginning to end. Students complaining about implementing a foundational algorithm instead of using a framework is depressing.
Not to mention that computer science and software engineering are such young fields that it seems unhealthy to take readily available abstractions as absolute givens. Everything stands to improve, even products and concepts that have been around for decades and that everyone uses.
> There's no substitute for the deep understanding you get by solving a complex problem yourself from beginning to end
Yes there is, watch someone else do it. In fact there are three ways to learn, as the saying goes: trial and error, copying, and insight. I'd be hard pressed to explain the difference of trial and error vs insight, but I wouldn't confuse them either, because only one of them is painful.
I disagree. To paraphrase the intro to my Linear Systems book "math is a contact sport." This applies to most intricate topics. If an expert takes you through a one hour tour of a subject, you will get the salient points, but there's a lot of intuition and that gets lost by you not struggling with the material on your own. That's why we have homework.
This is not as good. There's a lot of evidence from neuroscience that this leads to an illusion of competence. I.e. it's much easier to follow along through a sample solution than to craft a solution yourself. Until you craft the solution yourself, the knowledge won't actually be chunked as firmly in your brain.
NOTE: watching someone is a good way to get started, but until you do it on your own, you haven't learned it deeply, and it may be difficult to recall in a real situation.
I think there are intangible things that get lost when you watch someone else do something as opposed to doing it yourself. The exercise is about going through the mental motions of understanding the problem, designing a solution, and iterating on it until it's correct. The last part is all about learning from your own mistakes, seeing what specific things trip you up, so you know to improve on them. That's not something you can get by watching others.
I agree that there isn't enough time in a life to learn everything you'd want to first hand or from a low level of abstraction, but school should be a place to do as much of it as possible. Just my 2c.
Watching someone else do it is still less effective than bashing your head against the problem yourself before watching them do it.
Whether or not you succeed in solving it on your own, it will emotionally invest you in the problem and its solution while showing you what didn't work and having a better handle on the shape of the problem. This lets you get more out of seeing someone else work out the solution.
Not to mention that computer science and software engineering are such young fields that it seems unhealthy to take readily available abstractions as absolute givens. Everything stands to improve, even products and concepts that have been around for decades and that everyone uses.