I often wonder about it as I have read it many times in the last years. I never experienced it myself until very recently (there was probably a few attempt that bounced off from me and my mind deleted it). I can’t imagine what it could be thinking fat and red meat is bad… It just makes no sense to me 
And as far as I know, people rarely care about guidelines, they usually eat what they like or have… Ads seem to be more effective than education (even if it’s wrong education, oh it’s so annoying now that I know a few things and they often totally go against it).
So I had no problem with eating keto items ever (I don’t know what I thought about eating ONLY them but I probably was well aware I don’t know much about nutrition. as no one taught me much). Not eating the usual carby foods, that’s another matter… I ate every kind of food all my life (except meat, I never ate much of it until recently) and liked most of it.
Then I changed. I am super choosy now though I have my moments… But if I am hungry and want satiation, I always grab my normal, good, satiating food first. And if I am lucky or determined or carb poisoned, I stick to them.
We can learn. And relearn I suppose but as my knowledge and belief was almost nothing, maybe it was easier for me. (But I did thought vegetables and fruits are okay. I probably see the latter just natural candy since quite a few years but they are still so nice looking/feeling still (and when I went keto, I couldn’t live without them, not even for some days, I felt some need)! Most fruits are quite sugary and I know it’s the same fructose and glucose as in other sugars (and there is more but that’s not the point now) but it still feels very different and yep, it’s a bit different… It’s good my body nudges me since it knows how extreme low-carb feels. So I am aware it’s not proper food to me. Not like it ever was, it just made me hungry as all carbs, I needed fat and protein galore to get satiated. I just ate a ton of carbs on top in the past.)
Apropos fruit and temptation, my SO can’t adapt quickly to my strict carnivore right after my chaotic December and keeps asking if I want some of his fruit. It’s good I simply can’t be tempted now. It’s January. My fruit season is between June and December (I go very low in November too) and January is my lowest-carb month anyway after the never good enough December! And I am more determined than ever. I slowly add back items if I can’t last on my strict style anymore but fruit won’t be among them for months… I think. It is a drastic change now but I am good with drastic changes when I simply don’t eat what I don’t need or desire. Cutting out fruit is like cutting out sugar ages ago. Easy-peasy (even if it’s not 100% all year but still quite close. I took it seriously and we simply don’t have table sugar at home and the other, tasty sugars are rare and very neglected too. if we don’t consider fruits as we always have very much of that, canned, dried, fresh). (Though I like fruits way more than added sugar of any kind. But it’s not what matters. I liked pork the most during my several vegetarian years I didn’t need or want it. I just considered it the best tasting food.)
I am afraid I got carried away again…