Ethereum cons: smart contracts get hacked
Some write shitty smart contracts.
But, somehow, when someone did something allowed by the code, it turns out it wasn't in the spirit of the law, and so should be forked.
Oh great, now I can actually say something to my ethereum loving brother in law, btw do you have a source for this? Because when I try to search for any resource on the internet from before 2016 where Ethereum developers said that "code is law" I can't find it.