The amount of all-round bad advice on SO is staggering. It also encourages "copy-paste" coding and systems engineering, without the engineer really understanding the issue.
Except for those of us that learn by example. I taught myself sql the past month through stack exchange and PostgreSQL's manual. Typically, I'd find a stack overflow question that points me to the appropriate section of the manual to read.
There are a lot of bad answers. But it doesn't in courage copy-paste anymore than any other site with samples, including the reference manual. It isn't SO's fault if people don't try to understand the answers. But between the multiple comments and multiple answers it does a better job of indicating to the user that they still need to understand the solution.