Correlation and causation.
The original article in this thread states that dietary saturated fats do not turn into cholesterol. They are carried directly to the tissues by chylomicrons.
LDL is made in the liver from the saturated fat in the liver which in turn is made from carbohydrates.
So there is an apparent correlation between increased (although the baseline is not stated) consumption of butter and a rise in LDL produced by the liver.
It would have been good to see some kind of attempt at an explanation as to why butter was associated with a rise in liver-generated LDL.
The OP has a valid point; if butter apparently encourages a rise LDL then (regardless of the cause) it may be less healthy than olive oil and coconut oil assuming:
(1) The raised LDL is of the particle size considered to be dangerous.
(2) The risks associated with that particular fraction of LDL is accurately reported.
As already pointed out the diet of all participants would have to be strictly controlled so that all other aspects are the same. Same level of proteins, same level of carbohydrates.
Noted also, from
https://bmjopen.bmj.com/content/8/3/e020167:
"The effects of different dietary fats on lipid profiles, metabolic markers and health outcomes may vary not just according to the general classification of their main component fatty acids as saturated or unsaturated but possibly according to different profiles in individual fatty acids, processing methods
as well as the foods in which they are consumed or dietary patterns.".
My emphasis.
So the conclusion seems to be that there was a measured difference in lipid profile but the study has no idea if it is due to the type of fat consumed or due to other unrelated aspects such as chugging down olive oil or coconut oil changing what you eat during the day.
If it is assumed that the butter is mainly eaten on bread products then a simple explanation might be an increased consumption of bread. However we don't have enough information to draw this conclusion.
From the abstracts we don't even know if the participants on the olive oil were forbidden butter and coconut oil for 4 weeks (and so on for the others).
Bottom line is that, although there was a simplistic methodology, a significant difference in blood lipid profile was noted and this requires an explanation.
Yet another "more funding required for another study".