Because it is possible to create some transactions but I will have to then manually send all the transactions back to the main address, which would be a lot of unnecessary work if the actual value of tBTC is 0 USD and therefore it should be easily available. I dint know about that Ethereum Scam stuff, but I hope if this doesn't stop there will be just a second testnet or something like this to be able to stop these scammers to mess with people by hoarding all the coins.