They said that they have big investors backing this project and ready to buy all tokens and that's why there is only 20% of total supply for public sale. So I think there are a big investors behind the sense who brought a big percentage for some privileges and good discount.
I'm not sure but 20% for public sale is a normal amount for an ICO while there is a big percentage in the private sales, it served for a bigger investors which hold the coins or tokens for so many years.
And where you took information that this project collected private investments? If it is valid the truth, then 20% of the basic collecting are excellent result.