Problem is, coding isn't the kind of thing it's easy to share big tutorials and explanations with. beyond the basics & 'practicalities'(knowing the language,getting compilers working etc) i'm not sure people would have much to talk about. And bigger, better sites serve that purpose well enough.
Furthermore, for Source coding, the ground is already very, very well covered in the HLCoders email list, run by valve, which Mike Durand (the Valve mod community 'liason' as it were) often replies to very competently. Anyone into Source programming, I reccomend you
sign up there, and you'll never feel much of a need for a forum for it. Intelopers could probably never compete with that imho.
Unlike,say, modelling, it's the kind of thing where one person's query or problem (beyond the basics like getting the compiler working or figuring out syntax, as I said) probably won't be of that much value to anyone else, they tend to be overly specific questions, or things that coders think you should have already figured out yourself.
imho.
edit: just saw the mod-talk post that (presumably?) spawned this one; i think my criticism still stand: most of the programming questions that get asked round herwe are more general ones, for which much larger, better non-Source-specific resources and communities already exist