I disagree. Any tension (also an inapt word in this context) between art and craft in SF is no different that the tension between art and craft in any other genre. The craft of any short story, be it speculative fiction or not, is similar. Setting, character development, deft prose, crisp dialogue, plot development, etc. are tools of the craft of writing regardless of your choice of genre. Furthermore, the art isn't "very similar"--it's identical. Writing fiction is an art and its writers are artists. The "why" and "how" of their art, and especially the quality of their product, does not change the fact that it is art.
If you want to write high quality speculative fiction, you'd better be familiar with the genre. If you want to paint well in the abstract expressionist style, you'd better be familiar with the masters. Studying your milieu is not an issue of craft, its an issue of medium.