They would probably never say this publicly but I will speculate... The move is meant to move those(the majority) who would rather send an email off rather tha

They would probably never say this publicly but I will speculate... The move is meant to move those(the majority) who would rather send an email off rather than do their own research, or read the docs, to a more appropriate forum. And google employees can beef up their SO reps for answering the same questions over and over again. There's no incentive in answering most of those kinds of questions on a mailing list. And email is easy to ignore.