I disagree. It's actually quite simple to explain, especially since I had the same opinion back then. The equivalent would be somebody trying to learn a martial art and saying "I don't want to learn the basic stuff and how things work, show me how I can beat up somebody!"
You are supposed to learn and understand how these things actually work. Just learning the theory won't stick as good as if you actually implemented it. If you know the advantages and disadvantages between structures like a linked list, an std::vector, std::deque, etc. (and between binary trees, RB-trees, hash maps, std::map, etc.), you can actually make relevant and better decisions for system designs. Sure, you'll use vectors probably 99% of the time. But that remaining 1% might just be a heavy performance bottle neck.
I know that I have a situation like that in our engine. Since the array I needed was often changed and stuff was added at the beginning, this is quite a performance hit if you are using std::vector which has to move stuff around if you add stuff at the beginning. Adding elements at the beginning of an std::list has a complexity of only O(1) so it's much more suited for that kind of thing. I have another situation in our particle engine where it makes much more sense to use std::deque (or more specifically our derived implementation hltypes::Deque) than a simple std::vector because of some of the differences in how it is used and how it works internally.
Somebody without that kind of knowledge is not fit to be a system designer. Everybody can learn how to program these days, but programming engineers are the real heroes here. They are the ones who designed the new systems and languages everybody is using. They are the lead programmers and the bosses. Ever wonder why Java is so slow? It's a bit hard to explain, but it surely isn't because somebody used std::vector at the wrong place where he should have used std::list.
Sure, you may be pissed that you actually have to implement this now, but have some faith in your teachers. They wouldn't be teaching you this stuff if it wasn't relevant. Also, at one point you may have to work with a system that does not have an STL implementation (like early Android OS versions!) in which case you may have to provide your own and if you don't know how it works, you're just fucked.