Artists are mystics rather than rationalists. They leap to conclusions that logic cannot reach.
Conceptual art is only good if the idea is good.
In conceptual art the idea or concept is the most important aspect of the work
Most ideas that are successful are ludicrously simple
Conceptual art became the liberating idea that gave the art of the next 40 years its real impetus.
The other great development has been in photography, but that too was influenced by Conceptual art.