That's because is not a developers job to communicate. They are busy developing and working on the game. They answer everything they can through us as it's our job (community management and staff) to pass it along. On top of this, we have Q&As with BVV virtually every month on the website and Dev blogs every update.
Back in the days of a much smaller community, we used to be able to have a developer on the forum and answer a small topic. But it grew to the point where every one answer spawned 50 more questions and it would eventually take more than a week for developers to fully answer a full topic and all the questions within.
This isn't viable anymore. They are busy people with lots to do. But we have expanded communication everywhere else.