Oh, a search in motorcycle history will help you a lot. In the 80s it were those clip ons which turned a standard motorcycle into a hot street legal 'racing' bike.
Maybe it were the same riders which searched for the superbike handlebars to turn their supersport bikes into more comfortable street bikes in the 90s. Who knows, only those who made the metamorphosis will be able to answer.
And of course, these low mounted grips will only work with fit stomach muscles. That muscles will center and hold you, the hands on the grips are only for the steering impulse.
There is minimum one other thread telling this, if I remember right it covered the swallow & fat.