[Pseudoscience-is-malarkey (OP)]

No one can deny it, but why?

[alancalverd]

Thanks to millions of years of evolution there is an inherent preference to mate with a person with long legs.

Development of the femur depends not only on genetics but also on early nutrition, and bone marrow is a significant source of blood cells, so on average a person with long legs will have come from a family of successful hunters and be particularly healthy and able to pass on "good" genes.   

So anything that enhances the apparent length of legs, such as high heels, boots, high-cut swimwear, etc., stirs  a very basic instinct in a predominantly visual animal.

The fascination with stocking tops may be associated with this phenomenon. The gap  between stocking and panties calls attention to the length of a woman's thigh bones, in much the same way that the optimum length of a t-shirt sleeve (to cut exactly halfway along, and thus draw attention to the diameter of the bicep) adds to the attractiveness of a man.

[Petrochemicals]

I would say that it is a matter of preference.

https://en.m.wikipedia.org/wiki/Foot_fetishism