Speaking as someone who has been on there and posted a substantial number of answers I think the correlation between professional development skills is much stronger with open source contributions than "points" on a QA board.

IMO as someone who has been on stack exchange for a long time, while barely posting anything, ever. I would loathe feeling the need to have an active history of participation to boost my employment opportunities. At the same time, someone with a lot of good answers in their field should definitely include their profile in a job application.