Good subject matter is completely subjective, timing is dependent on the nature of your subject, quality of light is a subjective decision and technical perfection is mostly subjective. Good composition however has cultural norms and aesthetic standards that appear intuitive, but are in fact mostly analytical and part reference to the lineage of painting, cinema and still photography.
In that case, if I was forced to choose three, I'd go with education (in visual art, self-taught or otherwise, but disciplined and broad), composition*, and personal integrity.
*Composition - shouldn't be read as a puzzle with one learned, academic solution - it's mostly analytical in the sense that there is soooo much information* and each person will make their own conclusion. That's where personal integrity comes in. We're not computers, despite the word I've used below!
*Information - it's dangerous when making photographs to think in terms of 'objects', which only leads to the defeatist idea that "everything has been photographed". (I'll stop editing here, but...) Some photographers think in terms of 'objects' as symbols, which is information.
I think you have some very valid points. Well said.