I won't participate. I don't see the need, I can answer that question with a simple answer: Support. However, the question, how it's worded here, is biased and misleading, i.e. "...adhere to healthier dietary...", and "...their chosen dietary...".

So, the answer is "support", but what does that mean, really? It means everything you think it means in every sense of the word. It means it gets repeated ad nauseam by anybody and his dog everywhere you go, in everything you read, look at and listen to. It means everybody you know, knows the same thing, or at least repeats it to you, reminds you of what's good and bad. It means you get help from those who do the same thing you do, or at least who think you're doing the right thing. "Good job", "you're doing the right thing", "I'm there for you", etc, etc, etc.

On this forum, we do exactly that. But there's a much bigger "forum", it's called the Official Dietary Guidelines, and there isn't really a discussion forum for it, it's more of a mantra, a dogma, a propaganda, and a diet all in one confused mess, and it works like a charm cuz everybody and his dog really do sing the same hymn. There's even a professional entity called Dieticians that merely repeats the same thing.

It's called the Official Dietary Duidelines, but just to illustrate, let's change the name to Mr Dick's Sugar And Wheat Diet For Big Bucks. Now it's just another diet but with a giant industry behind it. There's no competition to speak of. All other diets are small time players with corresponding support - little to none.

Actually, the answer is even more obvious if the question instead is "why don't people stick to any particular diet", especially since that question is much more pertinent considering it's the single most repeated result in all dietary experiments ever done. Check for yourself. I mean, if LCHF - indeed any alternative diet - works so well, why do even just one of us go back to SAD?

Maybe I'm a little too cynical, even for my own taste, but whatever that's my take on this.