My view is that it really depends if a more in-depth answer would benefit someone asking the question. In some cases, like saying the answer is that they want a vocoder, it is probably worth putting an answer that not only says they need a vocoder, but also explains a bit about what it is and how one is used to accomplish their goal.
On the other hand, if it is simply something like "How do I connect x to y?" One line answers like "X is XLR, Y is quarter inch and this cable will connect them." is probably ok as additional details won't really be helpful here relative to what the person actually needs to know. It's really kind of a case by case thing.
Put another way, it isn't that one line answers are bad, it's that answers that don't give enough detail to really answer what the OP should know about the answer to their question are bad. There are plenty of questions where one line may be enough and all they should be worrying about right now. There are many others where that isn't really true.
That said, I would say it is generally preferable to have a short answer than an answer in comments. An answer in comments can't be marked as a solution by the OP if it answered what they needed. It also isn't possible for people to vote it down if they believe it to be incorrect. Given the choice between a short answer in comments and a short answer in an answer, the later is almost always preferable.
