If OTN is scam because IQ Option supports the project with financial investment,  so what about many other altcoins and ICO's ?

Both the BTC and all other ico's and altcoins present risks and none gives 100% guarantees of profits.
But some projects really stand out over others and should be followed closely, even involving risk.

OTN is no more risky than XRB or XVG, or others with high growth, all involve risk and all can make a lot of profit soon.

I heard a lot of criticism about XRP (Ripple) and a "crypto-currency expert" from my country said Ripple was going to melt because he had a company behind working with banks.

Leaving aside his convictions and personal ideologies, I decided to buy many XRP's and certainly not regret today!