Let me just add one thing into the equation.
There are a large number of requests that occur regularly, whose cause is simply the consequence of not fixing issues in the design.
Now, there are three things you can do in such a case:
1) Answer people when they ask about it
2) Create documentation so the question is answered once, authoritatively, and direct people to that answer
3) Refine the design so it doesn't need to be explained again
SMF's answer is invariably 1 and occasionally 2, and it's better now that there is the wiki but it doesn't solve the problem, it solves the symptoms - it answers the question, rather than trying to eliminate the need for the question to even be asked in the first place.
For example, Who's Online. How often does the question get asked about that, when admins see people accessing things they're not supposed to, and they start panicking that SMF is broken? Solution 1 happens consistently, solution 2 hasn't happened yet as far as I know, and I implemented solution 3 - if the user got an error, that fact is logged. If they were asked to log in, that fact is logged as well.
Maybe there will still be a question about it but I can guarantee I won't get the same number of questions that would normally come up - because I've taken the time to observe that there is a problem and the time to do something about it.
Another example is the Member Options in Themes configuration. How confusing is that? I haven't yet decided how to approach solving it but I know that breezing over it with a lick of paint as happened between SMF 1.1 and 2.0 isn't the answer. It's beyond unintuitive, and again solution 1 is common, solution 2 is not yet happening thoroughly.
Consider that when helping people, that the team have taken the view that it's better to answer peoples' questions and write documentation than it is to actually solve the problems that emerge. Honestly, it's like a doctor that is only too happy to prescribe painkillers to treat a pain than to investigate what's causing the pain and prescribing treatment for that.
In the discussion that occurred about removing the manual in 2.0 RC5, there were a lot of naysayers about it, and some people pointed out that if the UI were better designed, you wouldn't need a manual. Thing is, that's largely true. People point to things like Google when they want to find a site with 'help' but the thing is, the help doesn't tell them how to do the fundamentals of using it, it tells them how to do clever things or answers questions that have cropped up. (Seriously: how many sites do you know that actively have documentation about how to register on them?)
The bottom line: if you need documentation to explain how the basics work, you really are doing it wrong.