Am I an idiot for not understanding blockchain and ICO sales at all? Like, I get them somewhat in theory, but not understanding how they would actually be used?
Purchasers generally use them to get early and cheap access to potential speculative bubbles. Most "investors" fully intend to sell them as soon as it makes sense.
In other words there's no utility at all.
There are a few (e.g. Kik, Brave) that claim the coins will be used in some sort of platform, that presumably will sustain the value of the currency.
However one should always be hesitant to believe these claims because there are no regulatory agencies currently protecting investors in the case of ICO fraud.