There a are people discussing the correct usage of English grammar and how to best raise their kids, why not whether NoSQL is really the right solution? Flame Wars?
https://softwareengineering.stackexchange.com would probably do best for your sql/nosql thing, e.g. https://softwareengineering.stackexchange.com/q/54373
https://stackexchange.com/sites worth a browse
> You should only ask practical, answerable questions based on actual problems that you face. Chatty, open-ended questions diminish the usefulness of our site and push other questions off the front page.
This is sort of the fundamental limit of the format they chose.
https://codegolf.stackexchange.com/help/dont-ask also has it even though it encorages a significant number of answers per question (so, open ended)
Question tangent comments get sent there to try to keep the focus on Q&A rather than side back and forth. It's not gone permanently.
There are also persistent chat rooms for various topics. Their archives are easily searchable.
As you said though, there are a few StackExchange sites which deal with more "squishy" topics, like software design or parenting.
> If you have a question about...
> software development methods and practices > requirements, architecture, and design > quality assurance and testing > configuration management, build, release, and deployment