It's undeniable that the original intent of Stack Overflow is as you described; both Jeff and Joel have been very explicit about why they launched Stack Overflow and what its intended purpose was.
But Jeff left over 10 years ago and Joel was never very involved in the day-to-day operations. Since Jeff left things have been rather directionless; for a long time many Stack Overflow employees disagreed about lots of things and the net result was that ... nothing ever changed.
There's still many people who subscribe to this view of Stack Overflow, but also many who don't. In my own rant about Stack Overflow[1] I complained that these sort of useful questions being downvoted or closed.
In the end, this lack of direction results in a weird mish-mash site where different people are operating under different assumptions about what the "correct" behaviour ought to be, and it leaves everyone unhappy.