Just because you can't unit test an opinion doesn't mean we should stop discussing these things. Furthermore, most of the value I get from Stack Overflow comes from this particular class of questions and answers.
Q&A for professional and enthusiast programmers
Stack Exchange Network staging zone, where users come together to build new Q&A sites
Q&A for professional programmers interested in conceptual questions about software development
Q&A for professional system and network administrators
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Q&A for computer enthusiasts and power users
Q&A for power users of Apple hardware and software