I'd love to see somebody argue the other side of this, if they feel it's worthwhile, but here are my reasons for why I don't think there should be programming language specific stack exchanges:
- Stack Exchange has never allowed proposals that would steal significant traffic from an existing site, which this clearly would.
- You'd almost need to migrate all of the current C# related questions over to the new site, which would be a headache. That, or deal with repeats.
- C# programmers are already in the habit of going to stackoverflow.com, and you'd somehow have to get them to shift their thinking to go to a new site. In all likelihood, you'd lose a lot of people in the transition. A sub-point of this is that everyone would have to earn reputation all over again, so it would be hard to judge who the "trusted experts" are.
- I think there's a lot to be gained by the cross-pollination between languages on Stack Overflow. Even though a question may be language specific, sometimes somebody who is an expert in a different language will be able to shed unique and interesting light on the question.
- I think this would negatively affect the VB.Net people who have access to the exact same BCL/FCL, but who would lose a large collection of experts in that if they were funneled to a C# specific site.
It looks like this C# proposal was closed as a duplicate now, which I think is the right move... but I'd still actually be very interested in having someone present some counterpoints to this discussion.