I think that "mining coins" != "steal money", if previous version of SAFE allowed GPU miners and notaries mining with low diff - it can be mined both ways. And if somebody found a way how to mine it easier - this is not a reason to blame him.

p.s. I'm fully agree with polycryptoblog - jl777 is a very talented and versed in cryptography developer. If he found that SAFE has unchanged notaries public keys and told about it in any way (forum, chat channel, irc, slack, ... etc), it is his freedom. Description of opportunities - is not an attempt to steal something. And if somebody decided to mine SAFE using existing pubkeys - I see this as an attempt to demonstrate SAFE developers completely didn't understand forked sources, but not an attempt to steal something.