While I understand the point behind the example where you don't just have a car, you have a vehicle, it ties a vehicle to an engine which just isn't a sound des

While I understand the point behind the example where you don't just have a car, you have a vehicle, it ties a vehicle to an engine which just isn't a sound design either. i see many 'how to design' articles that replace one bad practice for another. what about bicycles? or sailboats? all in all, this is just too unfocused. one topic should have been addressed and addressed fully.