Because many of the smart contracts are not obliged to have currency movements such as a smart contract autarkic voting system right? where can this contribute to the growth of ethereum? basically nothing. I ask myself why do I see everyone justifying smart contracts as a good reason for ethereum to explode in the long run. I do not think at all what the contracts are to make her go to the moon. But if you got it wrong just let me know.
It depends on the platform of coin. And as I see it, it will be more productive if a token is used just like in arcadeshop. Token also can be used to advertise particular service like smart contract and what I see on facebook : dentacoin. Because if you give direct bitcoin or money , what is the guarantee that they will use their service. And if they sell it , it is guaranteed that the token will be use by someone for the service