I don't get all the hatred for ICOs. Nobody is forcing anybody to invest in them, and for something like filecoin there is at least a chance of something extrem

I don't get all the hatred for ICOs. Nobody is forcing anybody to invest in them, and for something like filecoin there is at least a chance of something extremely useful coming out of it. Many other ICOs seem pretty strange to me, but as long as I am not forced to invest in them, what's the problem?