It is too time consuming to send every offender a PM, Even then you may not even get a reply from them so I can't justify wasting the time. If the thread is just locked and they can come back to read it, when they read that they haven't followed rule A, B and C then it is justification for further action if they become a repeat offender.
Start a new thread if you want to talk about this, I already warned about posting stuff not related to this topic.