By this logic no photographer is an artist either. They just 'selected' a composition they liked. They didn't work to create any of their subjects, just walked up and took a picture.

Slowly coaxing a desired result out of a computer by painstakingly tweaking an algorithm over the course of hours or days doesn't sound like work to you? The computer wouldn't have just done it on its own if an artist didn't tell it what to do.

I think your definition of art is narrow-minded. Who are you to tell someone their work isn't art. Art is (and always has been) in the eye of the beholder.