StackExchange and StackOverflow are particularly useful and a waste of time

StackExchange and StackOverflow are website services where anyone can participate and gain a reputation.  With that reputation a person is granted more power and more visibility to both ask questions and give answers.  This means that popular people who give competent answers, and ask questions that other people can comprehend and also want the answers to, will gain all the power of speech and to limit or control input from others on the site.

Popularity... the old cliche strikes again.  Yes, on these sites popularity gives people power, which in the theory of specialization is a good thing, and since the primary subjects on these sites are about programming and computing you would think it wouldn't be anything like a classic high school popularity contest. Alas, popularity is become a well establish bane of their sites, wherein if you don't fit in with the language and opinions of the popular participants your work and contributions, however helpful or correct, will be voted down or ignored altogether.  Rather than staying pure to their policy statements for posting content, they have become biased by popularity.

You may think that is horrible and makes it a dingy place to search for truly helpful information, but not so.  If you were a participant who became popular, you could contribute much, and that doesn't make you a bad person. You may not gain enough power to affect the prejudice of other "top-dogs" but you could still fill out a massive amount of helpful question-and-answer advice. I have come across some really good questions and answers and even communicated directly with some really excellent participants.

So, you could think of it as a place where participating is excessively, or needlessly difficult, but searching for answers is easy. Your time is only more likely to be wasted if you intend to participate.