This would essentially achieve the same thing as increasing the merit requirement for a signature to 10, but yes, I would agree. Being able to earn money from displaying a signature should be an earned privilege and not available to any spammer who can beg, buy, trade or plagiarize their way to a single merit.

I would also support a change to increasing the requirement to 1 (or ideally 10) earned merit, regardless of rank. There are still plenty of spammers who only have a signature due to their airdropped merit.