In any case, IEO is a more promising investment. Scammers are not interested in their coin or token developing. Really serious projects pay a lot of money for IEO.
You may be right but we must also note that even if developers pay high for IEO, they can still take back that with ease because many will buy in the exchange even if that project is not legitimate. They can still conduct IEO even if that is a scam project.