Hi Lars,
The answer is already in your question "a place for high quality content or if broad audience appeal and visitor streams". We obviously cant have both. Right now SCN has struck a correct balance between these two after the recent changes to the RoE and SCN gamification rules.
The problem is being a community based portal we do have to give some weight-age to participation otherwise SCN would turn out to be a exclusive club for the technically strong and experienced. By saying this I am not supporting low quality content I am just saying that not everyone has the expertise or knowledge to put together a good blog or a discussion but everyone is enthusiastic about doing it in SCN. If people can take a comment or advice from the senior members and improve upon it then it would be really great.
There are always going to be people who forget to silence their cellphones in meeting and people who do not read the RoE before participating 
.
Benedict