Saying there is no distinction between art and math is like saying there is no distinction between art and sculptury. Yes it is a type of art, but is is a highly distinct skill set from painting.
Of course the way math is taught is about as much art as a coloring book, with a well defined key.
Both are wrong. Math and art are one and the same. Yes, this article in the link was correct that the problem lies in our education system, but there is no distinction between math and art. Our math just isn't applied enough or taught correctly, so students miss out on a true understanding of how math works. Look at da Vinci, that is a man who made no distinction between math and art.