People that say Ethereum is a scam probably have FOMO (Fear Of Missing Out) and at the same are forestalled by their lack of understanding and the (erroneous) conviction that theyre too late to join the game.
read this article it will help understand situation
I have not read the article, but in the last 2 months the etherium has fallen in price 3 times. Today there are no prerequisites to expect it to rise. Maybe it's not a scam, but I can not name a good coin.