Every time the reason is the same, they see a quick rich scheme and think that now it has to succeed and bring them the dream wealth. But the reality is different, there wasn´t any successful ICO that claimed guaranteed profit in advance. Look at EOS, they didn´t promise really nothing, but now it is one of the biggest cryptocurrency. 
Regarding eos, by the way I agree with you. Also first came to mind to me. In general, people should understand that free cheese is only in a mousetrap. All you need to do and think for yourself.