This reason is more important than either of the reasons you list: VC/PE firms are, by and large, staffed with professionals. ICO investors are, by and large,

This reason is more important than either of the reasons you list: VC/PE firms are, by and large, staffed with professionals. ICO investors are, by and large, amateurs (I settled on this word, after starting with several less nice ones). Amateurs are much more likely to get scammed than professionals.