Typically the better the sailor the more difficult it will be for that person to teach. The reason is being able to relate to the person who wants to learn to sail who knows "nothing". The excellent sailor knows "too much". The challenge for the better sailor is to go back to the very beginning where you knew nothing.
Gotta disagree with your statement. If you can find an experienced/excellent/long time sailor that can teach without immediately drowning the students with sailing jargon then you've got a keeper. The ones that can't are showing off their knowledge and not teaching anything.
