Another reason is the familiar (almost proud) pean of generations: "I can't
draw a straight line!" So many have been so effectively taught that they
cannot draw it has almost become an assumption and an expectation. And, if
that is the case, the obvious conclusion is that drawing is HARD and a
"specialist" art. This is an understanding that has been built
up(inadvertantly) in the context of education.
I don't know that you get around that effectively by saying "its good for
you." We need to learn hoe useful drawing is in daily life and how many
people do draw on a daily basis even if only covertly and with
Drawing is a skill and a process fundamental to much of the visual arts and
beyond the arts as well. Art comes into drawing with additional skill in
effectively translating perceptions to the process.of draawing.