i don't really eat at places like this but whenever I see some new fad with food especially if it something being referred to as superfood I normally just assume it is some hipster something or other that there is a certain demographic that would flock towards it... normally they buy Macintosh computers as well .
it's all marketing. Most of these superfoods were never used before because they have no practical application or taste horrible on their own. A little bit of marketing and made up claims about its qualities and now every trendy cafe has to have it! This is marketing at its finest.