This thing have been bugging me for months...
I agree that most listing questions are subjective. Asking for the best, feature comparison or recommendations cannot be objective because they depend only on personal experience (one praise his favorites while degrading others).
I still find StackOverflow useful when I got blocked by a problem and haven't found solution with 60 minutes Googling.
But sometimes I just want to learn about something I cannot find enough information of on internet.
To name a specific case: In my free time I'm working on my pet programming language and writing a compiler to it for the sake of getting better understanding of the compilers. I got quite far: semantic analysis is done, only the machine code generation is left. I learned x86 instructions, standard stack frames, calling conventions, ELF container format, so I can make it generate raw unoptimized code, that works, but slow of course. So I want to optimize it somehow, so I want to learn from what others do.
This would made me ask "What optimization techniques current C and C++ employ?" Hoping some advanced compiler guy eventually stumbles upon it, and adds to it. So I don't need to decypher the -O3 tricks from the disassembly listings and the GCC source code... So we could build a nice content here to learn from.
Seeing that similar questions got closed quickly. This wouldn't live so long either.
Reading the opinions most of them repeat the same mantra: not allowed and doesn't fit. But no one explains why they are inherently bad for the community, the moderators and the site. Also if it doesn't fit, why not enhance the site to make it fit somehow?
Sometimes I have a feeling that we are throwing out the baby with the bath water.
So to summarize:
Is SO reserved only for blocker issues you encounter in your everyday programming/development work?
If yes, than that would be the killer argument. So if you don't got stuck at a problem, go away. (Should be a first point of the site FAQ...)
OR
Or more generally: Should I ask a question on StackExchange sites if and only if I can expect someone to know the complete answer?
UPDATE
Ok, reworded the question a bit, since it the original implied the only 1 person can answer it. Probably the new version won't imply it. (I'm not a native English...)
A bit clarification: the common point of list questions that people only contribute to a large bucket, but no one out there who can know the entire list...