Why waste bitcoins on investing in businesses when fiat will do just fine?
One of my smartest decisions was to pay for my BFL pre-order with dollars last February, instead of using bitcoins. By the time I actually received my miner in late October, difficulty had increased so much that it took me a whole month to mine my first whole coin.
Of course if you have fiat you may invest using fiat. I 'm talking about guys that don't have enough fiat but bought hundreds or even thousands of coin early on and the only thing they do now is hoarding and waiting for others to give value to the ecosystem.