I'm not an expert in instinctive shooting (only 23 years with it...just a beginner) and I'm not sure anyone really is, but I do think MOST instinctive shooters would agree that its a close range style. Yes, its possible to develop some consistency at longer ranges, but its not the best method for what long range bow shooting is really geared to (at least in modern times)...which is target shooting. And target shooting seeks precision...which is better suited to aiming with artificial assistance... sights.
Those who choose the instinctive style over other methods might do so because of its connection to the romantic side of archery (what some might think of as traditional archery). Or maybe they choose it because its the archery style closest to what they are used to for an athletic interests ...honing an athletic ability...hand-eye coordination...throwing a ball, shooting a hoop, hitting the mark...that maximizes the personnal/self-reliant aspect and minimizes the artificial aspect. Except to understand and/or teach the concepts of 'instinctive' one doesn't need, or even want, to develop formal theories, mathematical calculations, or artificial help in undertaking it. Its more gutteral in nature and practice, something that calculating arrow trajectories or building sight pictures based on gapping definately cannot claim to be.
Sometimes we call athletes 'natural' or 'gifted' because they exhibit the ability to practice their sport without obvious effort or difficulty. Fluent, effective and entertaining to both participants and observers. A large part of the "charm" of athletics is the exultation and satisfaction one derives from physically executing those runs, throws, jumps and catches. Instinctive shooting is sort of the archery equivalent of that aspect of athletics. Except for a simple bow and a simple arrow the balance of the recipe is really just...you. No artificials. No 'concious' calculations. Just your innate ability, consistent form and physical execution honed through practiced repetition. Basic, satisfying, and yes potentially frustrating. But no pain no gain, right?
I like instinctive shooting, and I like it BECAUSE its a close range endeavor. It fits my hunting interests (to challenge myself to get close, minimizing wounding potential) and for me its more fun (like sports) to rely on innate coordination than artificial aids or calculated methodology. Some prefer the latter. Fine. Variety is what makes the world an interesting place.
I don't know if this helped at all with answering your question, but It sure makes me want to go out and shoot my bow...instinctively. You?