This site is extremely difficult to use for people who need the answer to a question.
Perhaps it would be best to describe my experience as a first time user. I originally asked my question anonymously, because I wasn't aware of how important it is to have an account. The question received two answers, one of which was off-topic in that it did not answer the question, but re-derived an example that was given in the question (apparently through carelessness). The second answer is correct and useful, but I need to ask a follow up question to get the answer I need. The useless answer was voted up twice, the useful answer has not been voted up.
So, naturally, I needed: 1) To comment (to ask my follow up question, and to point out that the answer that was voted up is not an answer at all). 2) To vote (to help correct the careless voting that had occurred). 3) To mark the question as answered, because there was a useful answer.
And here is the problem. All of these are impossible for a first time user.
I created an account, and (luckily) found a question that I could answer. (I have a background in artificial intelligence, and I found a machine learning question that I could answer in a useful way.) This gave me the 15 points I needed to be able to do anything at this site. I still don't have the 50 I need to correct the mistakes made at my question. I suppose I will have to wait until I find another two or three questions that relate in some way to AI -- which may never happen and at best will require me to visit this site every day for the foreseeable future. It seems that there is no easy way to get a useful answer to my question.
My experience has led me to conclude that this site is only truly useable by those who contribute to it, and does not effectively serve the larger community that needs its help. The site is self-serving and needs to reconsider its responsibility to the people it should be serving.