(...)or the fact that so many people in the world, (not just via this particular scam), continue to believe that there exist, 'magic' pills, potions or extracts to loose weight.
But people are lazy. And Stupid. Often stupid because they are lazy. Laziness is an inate human trait and we wouldn't be where we are now without putting so much effort into making things easier for ourselves.
Look at how many half-respectable websites have a panel with spam shit on every page. The ones listing "you wouldn't believe what happened next in these 12 amazing pictures": photoshopped tatt for anybody with a clue or "online companies hate you knowing this trick to buying iPads": preying on the greedy and desperate or "doctors hate this miracle diet pill" (with appalling mis-matched "before" and "after" shots): seeking the lazy and gullible. And this shit is repeated time and time again, everywhere - slowly reinforcing validity through repetition which is a key factor in brain washing and certain established organisation types.
There genuinely are some medical products that can drastically help with weight loss. However these have usually been found to have rather unpleasant side effects often centred around or involving serious malnutrition buy often others as well. Not even the corporate controlled drug testing processes have permitted these drugs through to market given how dangerous they are. There are some very clever investigations underway that are looking at slight twists on the theme but from what I understand, even these are quite a few years away from even approaching clinical testing - one of the complexities is that our digestive systems are pretty much unique to each individual given genetic, lifestyle, age and sex differences and the widely varying makeup of bacteria that inhabit our guts and that are critical to digestion.