IMO the other things that can make ICO are turned into scam are because some past investor are just like a little bit disappointment with how the project are performing after ICO. The hype on the last years on ICO things was very crazy, but the result are so imbalance compared to the their roadmap.
The most difficult aspect to comprehend for a significant number of investors is that most icos do not turn into a scam, most icos were created from the very beginning with the intention of scamming the investors, developers never had any intention of delivering on any of the promises that they made on the white paper, their website or in any other communication channel that they opened.