I don't think what marquez wrote as unintelligible but facile and a dressing up of an old concept of music composition, Reading my response to another topic, Marquez is like the doctor who professes to his patient the wonder of leeches because he read of a recent experiment where it had broad recuperative effects. So, he dresses the benefits of leeching in modern technological fluffery to convince the patient all his or her ills will be cured with leeching.
Simply put Marquez is saying greater complexity means the disposal of a greater variety of techniques to create conflicting emotional states in music. Greatness is seen as how well one is able to keep up this game. One way to keep up this game and make it sound convincing is to do as the doctor did about leeching in my prior metaphor - fluff it up in unnecessarily complex, obfuscating language. Too bad, because I like some of Marquez little experiments once in a blue moon.
You know this may sound off-topic but it isn't.
Writing music is oft times like the motivation and how we visit a sick person we know and, possibly, care about in the hospital. Despite all the noble altruistic reasons or how wonderful we are adhering to social convention by buying a card, flowers or some inspirational text or music, you are doing really for yourself. In the best case, it is done without insecurity or guilt and just because you love the person and enjoy the positive feelings you get from being there and "supporting" them - even though your visit could have the same effect as a dog trained to comfort patients in a hospital. At worst, you are doing out of duty or to emulate what your peers and family are doing because it is the right thing or to reinforce how great and valuable you are to the universe.
So you can approach the computer or paper with a dutiful adherence to your models - those you were drawn to or inculcated in you - or you could approach it as an activity you enjoy very much and not get too caught up in what historical figures or contemporaries have done and avoid unnecessary anxiety and insecurity. The best you can hope for is some people like it and even better some people want to perform it.
In sum, that is all artistic creation is - a visitation and possible communing with other people , beings, and/ or things and the intangible (and sometimes tangible) rewards you get. It will be brief, less than the time you blink an eye in the context of time, but I guess it is up to you if that moment truly, continually sucks or is quite often wonderful and engaging.
Formal training in itself has little bearing - rather it is the person's attitude and how they handle whatever training they receive as well as pursue. It can either aggravate or enhance the composition process.
BTW - The science of music is quite in its infancy - most music theory is just botanical classifications and descriptions of style divorced completely from significant socio-economic influences ( I am not a fan of the separation of musicology and music theory, but then again my knowledge of musicology is very little, please correct me if I err.