the top 1-2% have very large cash hoards they absolutely must invest. and they can't just go around opening laundromats, liquor stores and flipping houses. that's chicken feed. it requires too much attention. too much work.
there are challenges investing in the really big global growth stories (e.g. China): state ownership has the upper hand. they can be forced into a loss position by the state.
yet, vanishingly few are smart enough to predict the rise of Facebook or Google. so what can they do? take shots in the dark in the US tech economy until they hit something large.