I think there are two groups here, who can be driven by different factors.
T1s, particularly on MDI, often have greater food options than a T1 on fixed dose, mixed insulins, in that provided they can count the carbs, and grasp how their own bodies react to a lot of protein, they can usually match their medication to deal with the impact of sweet or carby foods. I do say usually, as there are some notoriously difficult scenario for T1s too.
For T2s, my observation would be as follows:
Most T2s arrive here because they are trying to find their way to managing their diet. Many are confused by conflicting information on the internet. I think I can be confident that most folks like that arriving here are almost immediately asked what their blood scores do throughout a typical day, and the vast majority respond that they have no idea as they have no meter. So, I would suggest the absolutely almost universal advice is to acquire a meter; either via their medics or to self-fund.
Thereafter, they are on a voyage of discovery. Let's face it, few new, testing T2s immediately achieve good blood scores whilst they are eating the big carbs - bread, potatoes, pasta, cereal, rice etc. Most are pretty quickly, if reluctantly trimming the carbs, and once the often seen seismic downward shifts in blood scores happen, they end up almost asking how low (carb) they can go.
To be honest, I hate labels, and I never talk about myself being on an LCHF diet. Unless they are well-clued in, they have no idea what that means. I express the way I eat as reduced carb, as that's my main focus, then I ensure I have my protein and top up the energy requirements by adding fats.
Personally, I cringe when I see newbies being told to do LCHF. How are they supposed to firstly know what the heck that accronym stands for? And just how emotive is the HF element, still? How many newbies rail against the fat; sometimes because they think they'll gain (more) weight, and some because they've already been told their lipids are high?
But, in summary, I think many people, through testing fall into LC eating, then as it starts to work, some can become quite evangelical about it. I honestly think most posters who enthuse a great deal are just trying to shorten the new person's learning curve, on their way to controlled and understood numbers.