Most people have their price. And these people who are supposed to be concerned about their reputations obviously had no reservations about being associated with Rossi who has been convicted of crimes for his past business practices.
Or perhaps, being Italian (or Greek, in the case of Stremenos) themselves, they have a better knowledge of the facts of Rossi's "criminal acts" than either you or I, and have decided that they aren't relevant.
But the RATIONAL (unlike psychoskeptic logic) thing is simply that Rossi's achievement is real. For it to "be a scam" would require Rossi to have suborned several hundred people (all the participants in the demos, all the folks associated with Defkalion, the principles of Ampenergo, and heaven only knows how many more.....and that all those people have managed to keep the scam secret all this time).
Sorry....that notion is simply nuts.