I think this is similar, in a way, to the debate about whether code should be commented. There are some who argue that code should be commentless because writing code without comments teaches other programmers to read and understand code quickly, and that it promotes the writing of good unit tests, because programmers should be able to know what code is supposed to do by reading through those anyway.
Real life, however, is never ideal, and the reality is that many (read: most) programmers simply don't have the time to go through hundreds of unit tests every time they need to debug complex code. Moreover, a lot of production code is less than ideal. For this reason, I think code needs to have comments.
Similarly, I think that any good question is usually made up of both code and prose to explain what's supposed to be going on. Even in cases where I don't think prose is necessary, I usually try to include it somewhere just as a good practice. In my professional career, I've found that the best senior-position teachers aren't the ones who've had the longest careers, but the ones who are able to communicate in English like human beings at least as well as, if not better than, code.