I don't think you're right. The mining machines are pointed towards Ghash pool owner and he becomes the owner of the mined block - that's how he can distribute

I don't think you're right. The mining machines are pointed towards Ghash pool owner and he becomes the owner of the mined block - that's how he can distribute the BTC to everyone who contributed. So in practice, he controls the whole hashing power and can perform the attack without users' consent.