Why is this canister with charcoal beautiful? It's just a metal thing with a bunch of rocks in it, right?
Well, it's because of what's behind the picture.
For only those who know though. We know that a bunch of really smart people at NASA had this crazy idea, and then some of them sat down and engineered a really difficult spacecraft, devised procedures, machined elements, and tested and tested again. Then they had to launch it into space and make sure that it got to some faraway place in space and execute a series of absurdly crazy series of steps to scoop a sample from an asteroid. Get back, crash to Earth but stay intact for them to collect what's inside. This is as insane engineering as it gets. Now when you look at this object you already know all of these things otherwise this object is not going to be meaningful to you.
Imagine that it is the same with art.
Perhaps not everything but most of the great art is a product of a series of great decisions that started when the artist was probably five. Maybe there is a lot of art out there that is just not to our taste or we don't understand well which is totally perfectly fine. A work of art is a product that is often judged against the entire body of work of the artist, this is the reason why we have what we call collectors of art. It is just difficult to know what you're looking at unless you know the processes involved, the materials, a bit of history of art, the artists themselves, and many many other things. You have to understand the materials on a fundamental level. You have to understand why oil paint is beautiful and what is a successful use of materials. You have to be competent in the kind of message the artist sends. Because no artwork appears in a vacuum. There's a lot of motivation behind work.
You have to be versed in art to understand it or to create it. You have to be versed in engineering to engineer.