Of course there are a number of people who are just unlucky and suffer structural problems or premature loss of muscle tone and have less ways to mitigate the problems.
I'd wager this could be resolved with the proper knowledge/treatment/exercises.
Excepting cases of a rare wasting disease, as far as I know loss of muscle tone really only has one cause: lack of use. If the way you're performing normal functions that would otherwise keep a muscle toned is altered so that the muscles surrounding it are continuously compensating and the muscle in question is continuously slacking off, then that would result in loss of tone over time.
The person I know who had their snoring resolved, my NMM specialist advised they take singing lessons. He was able to pinpoint precisely which muscles in the throat were lacking tone, and what type of exercises were required to return them to normal. If this person took singing lessons, they'd have to relearn how to express their vocal chords properly, which would correct the problem. Their normal talking voice was not utilizing their vocal chords properly, so over the decades the muscle tone in some areas decreased until it became problematic.
I have/had major structural problems in my throat, including lymph nodes that were chronically backed up (we're talking years of them constantly remaining huge - after an ultrasound of the area I was referred to a surgeon but decided against it) and Eustachian tubes that didn't drain properly, causing fluid to remain behind my eardrums. There were also times my airways only remained open if my head was in a certain position. The moment I tilted it upwards my airways would close off, but tucking my chin to my chest would immediately open them again. During these times a sip of water could take a full 30 seconds to go down. My doctor explained to me that the deep cervical fascia around my voicebox and esophagus was really
tight, and things were being tugged in weird directions.
After several months of treatment that included addressing this issue and feeling slight changes happening in that area, I encountered an unexpected breakthrough. I had been attempting to get myself to eat more slowly, chew better, enjoy it more, and all that good stuff, when in the state of relaxation and focus on what I was doing I casually swallowed in a manner that was totally different from what I was accustomed to. I felt food sliding down the front of my throat and for half a second my brain screamed at me YOU'RE GOING TO CHOKE
but then it was done, and my next thought was wait a minute, that felt more like the way things should be
It turned out that my motion of swallowing was very skewed. This animation
shows how normal swallowing is supposed to function. As a bolus of food is passing through the pharynx, it rests a moment on top of the closed epiglottis and into a little niche there before passing onto the esophagus. As near as can be figured out, my swallowing skipped this step entirely. After three swallows of soft food it literally became irritated and felt raw for days, because that area of my throat was so unaccustomed to anything solid touching it whatsoever.
I had a choking incident when I was little
that brought me very close to death. I suspect my incorrect swallowing can be dated to the aftermath of that incident. Somewhere, subconsciously, my brain decided that in order to eat without risk of choking I had to tense up all the muscles at the front of my throat and gulp quickly while keeping the muscles locked, so that the one particular area was not touched. This theory is strengthened by my experience of fighting through a week of my brain inexplicitely screaming at me the danger of impending choking even though the proper swallowing movement instinctively felt more natural to me and I knew good and well that I'd be okay.
So what happens when you take a decade or two of incorrect swallowing? Some muscles lose tone, others get too tight, and it's a slow decline into chaos. Again, just like with that person's snoring and their incorrect speaking. Take a few decades of talking wrong, and some things will be flabby while others are too tight.
One other quick example: I know a little girl who, as a toddler, had an extremely severe deep infection in the heel of her foot. Though it has long since healed, to this day, 4 years later, she does not put that heel down when she walks, but rather keeps it high and places her weight on the rest of the foot. Walking this way will inevitably cause her structural problems, if it hasn't already.
In my case, after a few weeks of correct swallowing as much as my throat could handle the lymph nodes in my throat shrunk by about 2/3rds from the size they'd constantly been at for years, one ear drained completely for the first time in about 7 years and a month or two later the other one partially drained. It was dramatic and a bit painful, and the sensation of relief was immense. I still can't tilt my head backwards without airways restricting, but it doesn't cut my air off completely and I haven't had to bring my chin to my chest in order to breathe either.
Based on my experience, anecdotal reports, and talking with my specialist, I have a really hard time believing that structural problems are just luck of the draw. Are they difficult to treat in a manner that actually heals them? Definitely. But I don't think they come about without reason.