Among all those many investors there must be some unfortunate people who got trapped into putting their money to unpopular IEO with shady exchange behind it and those are usually the one who whine the most.
Need to point out that most of the IEO you mentioned above is from popular exchange which is helped by the credibility of the exchange aswell as the huge liquidity in each exchange making it easy for investors to liquidate the token and making them less afraid while other less relevan exchange that offers IEO will just only have investors who dump after the token distributed.