Some of the "teachers" made themselves unwelcome by their treatment of others and it was their decision to cease contributing. Since we are all giving of our own time, users of the forums must be prepared to wait for answers. Many of us have busy lives, or matters unconnected to the forums which affect us. There are many who have given much time to the forums, but there are others who may quickly lose interest.
Sometimes it would help if users checked carefully for previous threads on the same problem. Certain topics come up only too often.