I was very interested when I found this branch of StackOverflow, and initially the questions and answers seemed rare, but reasonably interesting.
Lately I see, for example, 4 out of 11 active questions being asked by a single user, on trivial steps of a textbook stuff. I also see extremely general useless questions (what is data science, how to become data scientist).
I personally would be interested in the professional part of some combination of cross validated, data science and the algorithms tag on stackoverflow, in order to see how professional people solve problems.. Maybe the questions by all kinds of beginners could be asked in a single big stackoverflow.com.