His suggestions will only bring backlash. It will make scam and scammers hide, because when you disable signature in those boards, people will rarely visit them. So, so many accusations will go unattended to.
Inasmuch as i do not agree with the idea of OP but saying that there will be less engagements in those boards if signature codes are not displayed is not true, there are still sections and threads in the forum that generates enough traffics even though advertising codes are not shown.
Don't just make baseless statement. Can you mention the boards where signatures are not displayed, yet they still generate enough traffic? Just mention the board here and earn 1 merit from me. Have you taken a look at "serious discussion" board? How active is the board and others where signatures don't display?